diff --git a/go.sum b/go.sum
index 0fb267a..d98f2a5 100644
--- a/go.sum
+++ b/go.sum
@@ -23,6 +23,8 @@
 cloud.google.com/go v0.46.1/go.mod h1:a6bKKbmY7er1mI7TEI4lsAkts/mkhTSZK8w33B4RAg0=
 cloud.google.com/go v0.46.2 h1:CzaxDL0yS5OHsygr9wRodEjP93JHp67vzlRDGlVZTJw=
 cloud.google.com/go v0.46.2/go.mod h1:a6bKKbmY7er1mI7TEI4lsAkts/mkhTSZK8w33B4RAg0=
+cloud.google.com/go v0.46.3 h1:AVXDdKsrtX33oR9fbCMu/+c1o8Ofjq6Ku/MInaLVg5Y=
+cloud.google.com/go v0.46.3/go.mod h1:a6bKKbmY7er1mI7TEI4lsAkts/mkhTSZK8w33B4RAg0=
 cloud.google.com/go/bigquery v1.0.1/go.mod h1:i/xbL2UlR5RvWAURpBYZTtm/cXjCha9lbfbpx4poX+o=
 cloud.google.com/go/bigtable v1.0.0 h1:2DCxzxiuoWubL6J0yl4rUtFtIJAX566mcefQS3xy6us=
 cloud.google.com/go/bigtable v1.0.0/go.mod h1:N+NeT8ICfOM1Ek4CeP03mSESb2x+qLkSC0+CRBEsvAA=
@@ -32,6 +34,8 @@
 cloud.google.com/go/logging v1.0.0/go.mod h1:V1cc3ogwobYzQq5f2R7DS/GvRIrI4FKj01Gs5glwAls=
 cloud.google.com/go/pubsub v1.0.1 h1:W9tAK3E57P75u0XLLR82LZyw8VpAnhmyTOxW9qzmyj8=
 cloud.google.com/go/pubsub v1.0.1/go.mod h1:R0Gpsv3s54REJCy4fxDixWD93lHJMoZTyQ2kNxGRt3I=
+cloud.google.com/go/storage v1.0.0 h1:VV2nUM3wwLLGh9lSABFgZMjInyUbJeaRSE64WuAIQ+4=
+cloud.google.com/go/storage v1.0.0/go.mod h1:IhtSnM/ZTZV8YYJWCY8RULGVqBDmpoyjwiyrjsg+URw=
 contrib.go.opencensus.io/exporter/ocagent v0.4.12/go.mod h1:450APlNTSR6FrvC3CTRqYosuDstRB9un7SOx2k/9ckA=
 contrib.go.opencensus.io/exporter/ocagent v0.5.0/go.mod h1:ImxhfLRpxoYiSq891pBrLVhN+qmP8BTVvdH2YLs7Gl0=
 contrib.go.opencensus.io/exporter/ocagent v0.5.1/go.mod h1:oGSyf701BHqn69lMacwJJuyGzrk5eiCj86DxXhG2gfk=
@@ -144,6 +148,7 @@
 github.com/aws/aws-sdk-go v1.23.19/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/aws/aws-sdk-go v1.23.20/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/aws/aws-sdk-go v1.23.21/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
+github.com/aws/aws-sdk-go v1.23.22/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0 h1:HWo1m869IqiPhD389kmkxeTalrjNbbJTC8LXupb+sl0=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
@@ -700,6 +705,8 @@
 go.chromium.org/luci v0.0.0-20190913155846-d3de308203dc/go.mod h1:MIQewVTLvOvc0UioV0JNqTNO/RspKFS0XEeoKrOxsdM=
 go.chromium.org/luci v0.0.0-20190914205813-55da0cd4ce87 h1:iOGi4oDoTtuoBZtu9/KbZL1Fxb3Rqx6VIsxfyInUgA8=
 go.chromium.org/luci v0.0.0-20190914205813-55da0cd4ce87/go.mod h1:MIQewVTLvOvc0UioV0JNqTNO/RspKFS0XEeoKrOxsdM=
+go.chromium.org/luci v0.0.0-20190917014015-6692d4f00150 h1:CcrT8sWfrg+xjm00eaKP/n0smraRAXwFfFmmi0O7KtY=
+go.chromium.org/luci v0.0.0-20190917014015-6692d4f00150/go.mod h1:MIQewVTLvOvc0UioV0JNqTNO/RspKFS0XEeoKrOxsdM=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.opencensus.io v0.20.1/go.mod h1:6WKK9ahsWS3RSO+PY9ZHZUfv2irvY6gN279GOPZjmmk=
@@ -864,6 +871,8 @@
 go.skia.org/infra v0.0.0-20190915021605-2cd1d3e375a6/go.mod h1:NNOATpUJs3+qRnrbquVDUPucSbbUbkOuj88i8bhT+g0=
 go.skia.org/infra v0.0.0-20190915123010-19fff1dbcd61 h1:9eanIAgnYhwd+EDRa0G7z/FV8VzC7vUtpWTWLUxzHto=
 go.skia.org/infra v0.0.0-20190915123010-19fff1dbcd61/go.mod h1:86Ykxt2BlINOCEBF2baYPfreyZyzY5y7v4iGwBwHfD0=
+go.skia.org/infra v0.0.0-20190917002419-cb8a6e16ab41 h1:bkkcR4Lg0mTazrcK7umubN+8if8V+HrZCDPOHzukv+0=
+go.skia.org/infra v0.0.0-20190917002419-cb8a6e16ab41/go.mod h1:tR+J+Bt9q+h0vH7k68wA5q2/phPxtt15tfDIenkUTRI=
 go.skia.org/skia v0.0.0-20190503181046-70aab823547a h1:+9xKwnzXTkTu+2ZVhffRu0A60Jx/gOETiNlKkzqbnRY=
 go.skia.org/skia v0.0.0-20190503181046-70aab823547a/go.mod h1:oVrxmr1FXbVQ7PeGtZ28Kg5wPvB+bNsnw1n2j5rtfTY=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
@@ -971,6 +980,8 @@
 golang.org/x/net v0.0.0-20190909003024-a7b16738d86b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20190912160710-24e19bdeb0f2 h1:4dVFTC832rPn4pomLSz1vA+are2+dU19w1H8OngV7nc=
 golang.org/x/net v0.0.0-20190912160710-24e19bdeb0f2/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20190916140828-c8589233b77d h1:mCMDWKhNO37A7GAhOpHPbIw1cjd0V86kX1/WA9c7FZ8=
+golang.org/x/net v0.0.0-20190916140828-c8589233b77d/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190319182350-c85d3e98c914/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -1065,6 +1076,8 @@
 golang.org/x/sys v0.0.0-20190912141932-bc967efca4b8/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190913121621-c3b328c6e5a7 h1:wYqz/tQaWUgGKyx+B/rssSE6wkIKdY5Ee6ryOmzarIg=
 golang.org/x/sys v0.0.0-20190913121621-c3b328c6e5a7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3 h1:7TYNF4UdlohbFwpNH04CoPMp1cHUZgO1Ebq5r2hIjfo=
+golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.0.0-20160726164857-2910a502d2bf/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -1229,10 +1242,14 @@
 golang.org/x/tools v0.0.0-20190914235951-31e00f45c22e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20190916034716-92af9d69eff2 h1:cvSBP3q8DeS4up5q8ssbGdEtSGiDgRV7HBvOpr3g5RM=
 golang.org/x/tools v0.0.0-20190916034716-92af9d69eff2/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20190916172013-cb62a53de387/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20190917032747-2dc213d980bc h1:AzQrNvr65FlhSjBpg0eVCY43QLsuOqtzWGtjcBqT6J8=
+golang.org/x/tools v0.0.0-20190917032747-2dc213d980bc/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools/gopls v0.1.0/go.mod h1:p8Q0IUu6EEeGxqmoN/g6Et3gReLCGA7PtNRdyOxcWJE=
 golang.org/x/tools/gopls v0.1.1/go.mod h1:RYlHDmWjvTa1HuWNyEKa6/zzI2ums47cfsozmM0466w=
 golang.org/x/tools/gopls v0.1.3/go.mod h1:vrCQzOKxvuiZLjCKSmbbov04oeBQQOb4VQqwYK2PWIY=
 golang.org/x/tools/gopls v0.1.5/go.mod h1:ewacT0SpHccpfiFZFLB/R0sJKMz1HugGF8dhdrH1MNQ=
+golang.org/x/tools/gopls v0.1.6/go.mod h1:CB265kVlsa2ImPBrm+Kq0g5/l1XJHprToVr2xciXTT4=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/api v0.3.1/go.mod h1:6wY9I6uQWHQ8EM57III9mq/AjF+i8G65rmVagqKMtkk=
 google.golang.org/api v0.3.2/go.mod h1:6wY9I6uQWHQ8EM57III9mq/AjF+i8G65rmVagqKMtkk=
@@ -1291,6 +1308,8 @@
 google.golang.org/genproto v0.0.0-20190905072037-92dd089d5514/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
 google.golang.org/genproto v0.0.0-20190911173649-1774047e7e51 h1:Ex1mq5jaJof+kRnYi3SlYJ8KKa9Ao3NHyIT5XJ1gF6U=
 google.golang.org/genproto v0.0.0-20190911173649-1774047e7e51/go.mod h1:IbNlFCBrqXvoKpeg0TB2l7cyZUmoaFKYIwrEpbDKLA8=
+google.golang.org/genproto v0.0.0-20190916214212-f660b8655731 h1:Phvl0+G5t5k/EUFUi0wPdUUeTL2HydMQUXHnunWgSb0=
+google.golang.org/genproto v0.0.0-20190916214212-f660b8655731/go.mod h1:IbNlFCBrqXvoKpeg0TB2l7cyZUmoaFKYIwrEpbDKLA8=
 google.golang.org/grpc v1.17.0/go.mod h1:6QZJwpn2B+Zp71q/5VxRsJ6NXXVCE5NRUHRo+f3cWCs=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.19.1/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=