Upgrade rust/crates/proc-macro-nested to 0.1.7

Test: make
Change-Id: I5d115ac0948788c5b02f1db72551316973caf8ce
diff --git a/Cargo.toml b/Cargo.toml
index 0e57e36..f768689 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@
 
 [package]
 name = "proc-macro-nested"
-version = "0.1.6"
+version = "0.1.7"
 authors = ["David Tolnay <dtolnay@gmail.com>"]
 description = "Support for nested proc-macro-hack invocations"
 license = "MIT OR Apache-2.0"