Tweak travis config

.travis.yml

@@ -1,22 +1,33 @@
 language: rust
-rust:
-  - stable
-  - beta
-  - nightly
+sudo: false
+
 matrix:
   include:
-    # Minimum version supported
     - rust: 1.13.0
       install:
       script: cargo build
+    - rust: stable
+      env: TARGET=x86_64-unknown-linux-gnu NO_ADD=1
+    - rust: stable
+      env: TARGET=i686-unknown-linux-gnu
+    - os: osx
+      env: TARGET=x86_64-apple-darwin NO_ADD=1
+    - rust: beta
+      env: TARGET=x86_64-unknown-linux-gnu NO_ADD=1
+    - rust: nightly
+      env: TARGET=x86_64-unknown-linux-gnu NO_ADD=1
+
+    - rust: nightly
+      before_script:
+        - pip install 'travis-cargo<0.2' --user && export PATH=$HOME/.local/bin:$PATH
+      script:
+        - cargo doc --no-deps --all-features
+      after_success:
+        - travis-cargo --only nightly doc-upload
 
-sudo: false
 install:
-  - if [ "$TRAVIS_OS_NAME" = "linux" ]; then OS=unknown-linux-gnu; else OS=apple-darwin; fi
-  - export TARGET=$ARCH-$OS
   - if [ -z "$NO_ADD" ]; then rustup target add $TARGET; fi
-before_script:
-  - pip install 'travis-cargo<0.2' --user && export PATH=$HOME/.local/bin:$PATH
+
 script:
   - cargo build --verbose
   - cargo test --verbose
@@ -27,21 +38,14 @@ script:
   - cargo doc
   - cargo clean && cargo build
   - rustdoc --test README.md -L target/debug -L target/debug/deps
-after_success:
-  - travis-cargo --only nightly doc-upload
+
 env:
   global:
     secure: "CBtqrudgE0PS8x3kTr44jKbC2D4nfnmdYVecooNm0qnER4B4TSvZpZSQoCgKK6k4BYQuOSyFTOwYx6M79w39ZMOgyCP9ytB+tyMWL0/+ZuUQL04yVg4M5vd3oJMkOaXbvG56ncgPyFrseY+FPDg+mXAzvJk/nily37YXjkQj2D0="
 
-  matrix:
-    - ARCH=x86_64 NO_ADD=1
-    - ARCH=i686
 notifications:
   email:
     on_success: never
-os:
-  - linux
-  - osx
 addons:
   apt:
     packages: