Make macOS the first travis build job (it is slowest)

.travis.yml

@@ -61,6 +61,13 @@ matrix:
   #  compiler: ": #GHC 7.10.3"
   #  addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.3,happy-1.19.5,alex-3.1.7], sources: [hvr-ghc]}}
   
+  ##### OSX test via stack #####
+
+  # Build on macOS in addition to Linux
+  - env: BUILD=stack ARGS=""
+    compiler: ": #stack default osx"
+    os: osx
+
   ##### CABAL #####
   
   - env: BUILD=cabal GHCVER=8.0.2 CABALVER=1.24 HAPPYVER=1.19.5 ALEXVER=3.1.7
@@ -117,11 +124,6 @@ matrix:
     compiler: ": #stack nightly"
     addons: {apt: {packages: [libgmp-dev]}}
 
-  # Build on macOS in addition to Linux
-  - env: BUILD=stack ARGS=""
-    compiler: ": #stack default osx"
-    os: osx
-
   # Travis includes an macOS which is incompatible with GHC 7.8.4
   #- env: BUILD=stack ARGS="--resolver lts-2"
   #  compiler: ": #stack 7.8.4 osx"