enable caching for ci (#2799)

* enable cache

* caching on mac

* fix ci caching on mac

* fix

* add mac cache

* added homebrew cache and pretty print yaml (+ structural ordering)

* cleanup

* fix ccache on mac

* testing workaround

https://github.com/travis-ci/travis-ci/issues/7456#issuecomment-296505058

* try xcode7.3 instead of workaround

* cache timout value

more time for cache to upload

.travis.yml

@@ -1,5 +1,7 @@
+sudo: required   # forces legacy build infrastructure
+
 language: cpp
-sudo: required
+
 matrix:
   fast_finish: true
   include:
@@ -10,21 +12,28 @@ matrix:
     dist: trusty
     env: BUILDTYPE=Release DIST=trusty
   - os: osx
-    osx_image: xcode6.4
+    osx_image: xcode7.3
     env: BUILDTYPE=Debug
+    cache:
+      ccache: true
+      timeout: 360 # 6min timeout for cache uploading instead default 3
+      directories:
+        - $HOME/Library/Caches/Homebrew   # cache Homebrew ressources
   - os: osx
-    osx_image: xcode6.4
+    osx_image: xcode7.3
     env: BUILDTYPE=Release
-script: "./travis-compile.sh"
+    cache:
+      ccache: true
+      timeout: 360 # 6min timeout for cache uploading instead default 3
+      directories:
+        - $HOME/Library/Caches/Homebrew   # cache Homebrew ressources
+
+cache: ccache
+
 install: "./travis-dependencies.sh"
-cache: apt
+
-notifications:
+script: "./travis-compile.sh"
-  webhooks:
+
-    urls:
-    - https://webhooks.gitter.im/e/d94969c3b01b22cbdcb7
-    on_success: change
-    on_failure: change
-    on_start: never
 deploy:
   provider: releases
   api_key:
@@ -37,4 +46,13 @@ deploy:
   on:
     tags: true
     repo: Cockatrice/Cockatrice
-    condition: $BUILDTYPE = Release
+    condition: $BUILDTYPE = Release
+
+notifications:
+  webhooks:
+    urls:
+    - https://webhooks.gitter.im/e/d94969c3b01b22cbdcb7
+    on_success: change
+    on_failure: change
+    on_start: never
+    

travis-compile.sh

@@ -8,6 +8,7 @@ mkdir -p build
 cd build
 prefix=""
 if [[ $TRAVIS_OS_NAME == "osx" ]]; then
+  export PATH="/usr/local/opt/ccache/libexec:$PATH"
   prefix="-DCMAKE_PREFIX_PATH=$(echo /usr/local/opt/qt*/)"
 fi
 if [[ $TRAVIS_OS_NAME == "linux" ]]; then

travis-dependencies.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 if [[ $TRAVIS_OS_NAME == "osx" ]] ; then
-  brew update > /dev/null
+  brew install ccache   # enable caching on mac (PATH only set in travis-compile.sh)
   brew install --force qt@5.7
   brew install protobuf
 else