CI: add nightly features

.travis.yml

@@ -2,14 +2,23 @@ language: rust
 matrix:
   include:
     - rust: stable
+      os: linux
+      env: FEATURES=''
+    - rust: stable
+      os: osx
       env: FEATURES=''
     - rust: beta
+      os: linux
+      env: FEATURES=''
+    - rust: beta
+      os: osx
       env: FEATURES=''
     - rust: nightly
+      os: linux
+      env: FEATURES=nightly
+    - rust: nightly
+      os: osx
       env: FEATURES=nightly
-os:
- - linux
- - osx
 cache:
  directories:
   - $HOME/.cargo

appveyor.yml

@@ -33,4 +33,4 @@ artifacts:
 build: false
 
 test_script:
-  - cargo test --no-fail-fast --features generic --no-default-features
+  - cargo test --no-fail-fast --features nightly generic --no-default-features

build.rs

@@ -12,7 +12,7 @@ pub fn main() {
         if val == "1" && key.starts_with(feature_prefix) {
             let krate = key[feature_prefix.len()..].to_lowercase();
             match krate.as_ref() {
-                "default" | "unix" | "generic" | "test_unimplemented" => continue,
+                "default" | "unix" | "generic" | "nightly" | "test_unimplemented" => continue,
                 _ => {},
             }
             crates.push(krate.to_string());