signal: Tweak travis config

.travis.yml

@@ -1,19 +1,25 @@
 language: rust
-
-rust:
-  - stable
-  - beta
-  - nightly
 sudo: false
-before_script:
+
+matrix:
+  include:
+    - rust: stable
+    - os: osx
+    - rust: beta
+    - rust: nightly
+
+    - rust: nightly
+      before_script:
         - pip install 'travis-cargo<0.2' --user && export PATH=$HOME/.local/bin:$PATH
-script:
-  - cargo build
-  - cargo test
-  - cargo doc --no-deps
-  - rustdoc --test README.md -L target/debug/deps
-after_success:
+      script:
+        - cargo doc --no-deps --all-features
+      after_success:
         - travis-cargo --only nightly doc-upload
+
+script:
+  - cargo test
+  - rustdoc --test README.md -L target/debug/deps
+
 env:
   global:
     - secure: "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"
@@ -21,6 +27,3 @@ env:
 notifications:
   email:
     on_success: never
-os:
-  - linux
-  - osx