Travis: Move before_deploy out of matrix block (#229)

.travis.yml

@@ -6,7 +6,6 @@ matrix:
   include:
   - rust: 1.21.0
   - rust: stable
-    before_deploy: cargo doc --all --no-deps
   - os: osx
   - rust: beta
   - rust: nightly
@@ -31,6 +30,9 @@ script:
         cargo test --manifest-path tokio-reactor/Cargo.toml --features unstable-futures
     fi
 
+before_deploy:
+  - cargo doc --all --no-deps
+
 deploy:
   provider:  pages
   skip_cleanup: true