chore(ci): test features on travis

Author: dignifiedquire

.travis.yml

@@ -11,3 +11,17 @@ matrix:
   allow_failures:
     - rust: nightly
   fast_finish: true
+
+script:
+ - |
+   if [ ${TRAVIS_RUST_VERSION} = "nightly" ]; then
+       cargo build --verbose $ARGS --features "nightly";
+       cargo test --verbose --features "nightly";
+       cargo doc --verbose --features "nightly";
+   fi
+ - cargo build --verbose
+ - cargo test --verbose
+ - cargo doc --verbose
+ - cargo build --verbose --no-default-features
+ - cargo test --verbose --no-default-features
+ - cargo doc --verbose --no-default-features