Reorder builds to improve build times

The main issue is that all iOS builds are in a block and there are only 5
simultaneous builds allowed by our Travis CI plan. So if there's a backlog
of iOS builders, then the entire build process stalls. So instead of having
them all clumped together, distribute the Mac and iOS builds throughout the
build pipeline.

Author: Susurrus

.travis.yml

@@ -12,7 +12,9 @@ env:
 
 matrix:
   # These are all the build jobs. Adjust as necessary. Comment out what you
-  # don't need
+  # don't need. The iOS/Mac builds are distributed throughout because Travis
+  # likes to have a big backlog on builds on those machines. This way at least
+  # all of the other jobs can finish while waiting on those builds.
   include:
     # Android
     - env: TARGET=aarch64-linux-android DISABLE_TESTS=1
@@ -21,70 +23,63 @@ matrix:
       rust: 1.13.0
     - env: TARGET=armv7-linux-androideabi DISABLE_TESTS=1
       rust: 1.13.0
+    - env: TARGET=aarch64-apple-ios DISABLE_TESTS=1
+      rust: 1.13.0
+      os: osx
     - env: TARGET=i686-linux-android DISABLE_TESTS=1
       rust: 1.18.0
     - env: TARGET=x86_64-linux-android DISABLE_TESTS=1
       rust: 1.18.0
 
-    # iOS
-    - env: TARGET=aarch64-apple-ios DISABLE_TESTS=1
+    # Linux
+    - env: TARGET=aarch64-unknown-linux-gnu
       rust: 1.13.0
-      os: osx
     - env: TARGET=armv7-apple-ios DISABLE_TESTS=1
       rust: 1.13.0
       os: osx
-    - env: TARGET=armv7s-apple-ios DISABLE_TESTS=1
-      rust: 1.13.0
-      os: osx
-    - env: TARGET=i386-apple-ios DISABLE_TESTS=1
-      rust: 1.13.0
-      os: osx
-    - env: TARGET=x86_64-apple-ios DISABLE_TESTS=1
-      rust: 1.13.0
-      os: osx
-
-    # Linux
-    - env: TARGET=aarch64-unknown-linux-gnu
-      rust: 1.13.0
     - env: TARGET=arm-unknown-linux-gnueabi
       rust: 1.13.0
     - env: TARGET=arm-unknown-linux-musleabi DISABLE_TESTS=1
       rust: 1.14.0
     - env: TARGET=armv7-unknown-linux-gnueabihf
       rust: 1.13.0
+    - env: TARGET=armv7s-apple-ios DISABLE_TESTS=1
+      rust: 1.13.0
+      os: osx
     - env: TARGET=i686-unknown-linux-gnu
       rust: 1.13.0
     - env: TARGET=i686-unknown-linux-musl
       rust: 1.13.0
     - env: TARGET=mips-unknown-linux-gnu
       rust: 1.13.0
+    - env: TARGET=i386-apple-ios DISABLE_TESTS=1
+      rust: 1.13.0
+      os: osx
     - env: TARGET=mips64-unknown-linux-gnuabi64
       rust: 1.13.0
     - env: TARGET=mips64el-unknown-linux-gnuabi64
       rust: 1.13.0
     - env: TARGET=mipsel-unknown-linux-gnu
       rust: 1.13.0
+    - env: TARGET=x86_64-apple-ios DISABLE_TESTS=1
+      rust: 1.13.0
+      os: osx
     - env: TARGET=powerpc-unknown-linux-gnu DISABLE_TESTS=1
       rust: 1.13.0
     - env: TARGET=powerpc64-unknown-linux-gnu
       rust: 1.13.0
     - env: TARGET=powerpc64le-unknown-linux-gnu
       rust: 1.13.0
+    - env: TARGET=i686-apple-darwin
+      rust: 1.13.0
+      os: osx
     - env: TARGET=s390x-unknown-linux-gnu DISABLE_TESTS=1
       rust: 1.13.0
     - env: TARGET=x86_64-unknown-linux-gnu
       rust: 1.13.0
     - env: TARGET=x86_64-unknown-linux-musl
       rust: 1.13.0
 
-    # OSX
-    - env: TARGET=i686-apple-darwin
-      rust: 1.13.0
-      os: osx
-    - env: TARGET=x86_64-apple-darwin
-      rust: 1.13.0
-      os: osx
-
     # *BSD
     # FreeBSD i686 and x86_64 use BuildBot instead of Travis
     # Note that i686-unknown-freebsd is actually using stable Rust instead of
@@ -94,6 +89,10 @@ matrix:
     - env: TARGET=x86_64-unknown-netbsd DISABLE_TESTS=1
       rust: 1.13.0
 
+    - env: TARGET=x86_64-apple-darwin
+      rust: 1.13.0
+      os: osx
+
     # Testing beta on main targets
     - env: TARGET=x86_64-unknown-linux-gnu
       rust: beta