Build on OS X too

Related: remacs#38

.travis.yml

@@ -1,10 +1,12 @@
 language: rust
 cache: cargo
 rust:
-  - 1.14.0
   - stable
   - beta
   - nightly
+os:
+  - linux
+  - osx
 
 addons:
   apt:
@@ -20,7 +22,9 @@ env:
 script:
   # Configure Emacs for building
   - ./autogen.sh
-  - ./configure
+  # These configure flags are only required on OS X.
+  # TODO: remove them.
+  - ./configure --without-makeinfo --with-xpm=no --with-gif=no --with-gnutls=no
   - make -j 3
 
   - make check
@@ -30,9 +34,12 @@ notifications:
   email: false
 
 matrix:
-  allow_failures:
-    - rust: nightly
   exclude:
-    # Since stable is currently 1.14.0, there's no point running 1.14.0 twice.
-    # TODO: remove this once 1.15.0 is out.
-    - rust: stable
+    # OS X only builds on nightly, see https://github.com/Wilfred/remacs/pull/112
+    - os: osx
+      rust: stable
+    - os: osx
+      rust: beta
+    # Don't build nightly on linux, to keep our build quicker.
+    - os: linux
+      rust: nightly