use multibuild facilities for ccache

.travis.yml

@@ -5,7 +5,7 @@ env:
         - TEST_DEPENDS="numpy==1.11.1"
         # params to bdist_wheel. used to set osx build target.
         - BDIST_PARAMS=""
-
+        - USE_CCACHE=1
         - PLAT=x86_64
         - UNICODE_WIDTH=32
         - secure: "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"

config.sh

@@ -100,12 +100,6 @@ function pre_build {
     # see https://docs.brew.sh/Manpage , "info formula" section
     export HOMEBREW_NO_GITHUB_API=1
 
-    # https://docs.travis-ci.com/user/caching/#ccache-cache
-    # No need to allow rc 1 -- if this triggers a timeout,
-    #  something is clearly wrong
-    brew_install_and_cache_within_time_limit ccache
-    export PATH="/usr/local/opt/ccache/libexec:$PATH"
-
     echo 'Installing QT4'
     brew tap | grep -qxF cartr/qt4 || brew tap cartr/qt4
     brew tap --list-pinned | grep -qxF cartr/qt4 || brew tap-pin cartr/qt4