chore: increment minimum rustc version

indiv0 · indiv0 · commit b04ef030e23f · 2017-11-24T09:41:18.000-05:00
Increment the minimum rustc version to support the carrier trait ("?").
diff --git a/.travis.yml b/.travis.yml
@@ -16,7 +16,7 @@ rust:
   - stable
   # and the first stable one (this should be bumped as the minimum Rust version
   # required changes)
-  - 1.9.0
+  - 1.13.0
 os:
   - linux
 cache: cargo
