Also test on Rust stable.

SimonSapin · SimonSapin · commit 72cf5e4ea846 · 2015-05-19T00:04:34.000-04:00
diff --git a/.travis.yml b/.travis.yml
@@ -3,6 +3,7 @@ language: rust
 rust:
   - nightly
   - beta
+  - stable
 
 script:
   - cargo build --verbose

-Original file line number
+Diff line change
 rust:
   - nightly
   - beta
 +  - stable
 script:
   - cargo build --verbose