diff --git a/go.sum b/go.sum
index 6b17a5a..fcdf3ab 100644
--- a/go.sum
+++ b/go.sum
@@ -134,6 +134,7 @@
 github.com/aws/aws-sdk-go v1.23.15/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/aws/aws-sdk-go v1.23.16/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/aws/aws-sdk-go v1.23.17/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
+github.com/aws/aws-sdk-go v1.23.18/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=
@@ -666,6 +667,8 @@
 go.chromium.org/luci v0.0.0-20190906003230-2b8b37b10d7f/go.mod h1:MIQewVTLvOvc0UioV0JNqTNO/RspKFS0XEeoKrOxsdM=
 go.chromium.org/luci v0.0.0-20190908081726-56d87b080d76 h1:D0hxhAynrlcec1/rhewPbBter7+Wz3xObdglqSazaJs=
 go.chromium.org/luci v0.0.0-20190908081726-56d87b080d76/go.mod h1:MIQewVTLvOvc0UioV0JNqTNO/RspKFS0XEeoKrOxsdM=
+go.chromium.org/luci v0.0.0-20190909234225-895c16d58238 h1:F37rsPIGfHM+y0TDM25IKc1peMRM8dfugXlcyfe9xfE=
+go.chromium.org/luci v0.0.0-20190909234225-895c16d58238/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=
@@ -818,6 +821,8 @@
 go.skia.org/infra v0.0.0-20190907052920-7ce9afae2d57/go.mod h1:cIdnLNyhs40+5Ttlhr5Bs/FaukRuAvQY3wcH3sJM7/I=
 go.skia.org/infra v0.0.0-20190908193410-70e4432e07bb h1:fv6liLHqJj522o1RHQoD6sBHH8R/yprfN6gIk47kGWw=
 go.skia.org/infra v0.0.0-20190908193410-70e4432e07bb/go.mod h1:FDiraX4F+JxCf3Ev8jyX9hBS3QZWEe25rulFhFL15+8=
+go.skia.org/infra v0.0.0-20190909224843-3b9fd57793be h1:CrUSIGCDIZUaHeC4HmXhGCx8yPNQbzhrYXBjhqK7+zA=
+go.skia.org/infra v0.0.0-20190909224843-3b9fd57793be/go.mod h1:VvmyCbYoMksnbNcH9YZRw/dc4ahCUPJTSm1K9rjn47c=
 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=
@@ -840,6 +845,7 @@
 golang.org/x/crypto v0.0.0-20190820162420-60c769a6c586/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190829043050-9756ffdc2472/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190907121410-71b5226ff739/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20190909091759-094676da4a83/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190429183610-475c5042d3f1/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
@@ -866,6 +872,7 @@
 golang.org/x/lint v0.0.0-20190301231843-5614ed5bae6f/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/lint v0.0.0-20190409202823-959b441ac422/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
+golang.org/x/lint v0.0.0-20190909230951-414d861bb4ac/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/mobile v0.0.0-20190312151609-d3739f865fa6/go.mod h1:z+o9i4GpDbdi3rU15maQ/Ox0txvL9dWGYEHz965HBQE=
 golang.org/x/mobile v0.0.0-20190415191353-3e0bab5405d6/go.mod h1:E/iHnbuqvinMTCcRqshq8CkpyQDoeVncDDYHnLhea+o=
 golang.org/x/mobile v0.0.0-20190509164839-32b2708ab171/go.mod h1:E/iHnbuqvinMTCcRqshq8CkpyQDoeVncDDYHnLhea+o=
@@ -999,6 +1006,8 @@
 golang.org/x/sys v0.0.0-20190904154756-749cb33beabd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190907184412-d223b2b6db03 h1:b3JiLYVaG9kHjTcOQIoUh978YMCO7oVTQQBLudU47zY=
 golang.org/x/sys v0.0.0-20190907184412-d223b2b6db03/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190909082730-f460065e899a h1:mIzbOulag9/gXacgxKlFVwpCOWSfBT3/pDyyCwGA9as=
+golang.org/x/sys v0.0.0-20190909082730-f460065e899a/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=
@@ -1147,6 +1156,8 @@
 golang.org/x/tools v0.0.0-20190907020128-2ca718005c18/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20190909030654-5b82db07426d h1:PhtdWYteEBebOX7KXm4qkIAVSUTHQ883/2hRB92r9lk=
 golang.org/x/tools v0.0.0-20190909030654-5b82db07426d/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20190910044552-dd2b5c81c578 h1:f0Gfd654rnnfXT1+BK1YHPTS1qQdKrPIaGQwWxNE44k=
+golang.org/x/tools v0.0.0-20190910044552-dd2b5c81c578/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=