fix(deps): cargo update (#103)

Author: ashleygwilliams

.travis.yml

@@ -5,7 +5,7 @@ matrix:
   include:
 
   # tests pass
-  - rust: nightly-2018-08-06
+  - rust: nightly-2018-09-09
     script:
     - cargo test --all --locked
     - rustup component add rustfmt-preview