Add caching

Mainly to have a backup cache for new branches (although this won't
help that much because of the differences between ZEO4 and ZEO5,
still...

Also stop testing on mac. I do that enough already. :)

Also, use a simpler leaner install script.

.travis.yml

@@ -12,24 +12,12 @@ matrix:
           python: 3.5
         - os: linux
           python: pypy
-        - os: osx
-          language: generic
-          env: TERRYFY_PYTHON='homebrew 2'
-        - os: osx
-          language: generic
-          env: TERRYFY_PYTHON='macpython 3.4'
-        - os: osx
-          language: generic
-          env: TERRYFY_PYTHON='homebrew 3'
-before_install:
-    - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then git clone https://github.com/MacPython/terryfy; fi
-    - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then source terryfy/travis_tools.sh; fi
-    - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then get_python_environment $TERRYFY_PYTHON venv; fi
-    - if [[ "$TERRYFY_PYTHON" == "homebrew 3" ]]; then alias pip=`which pip3` ; fi
 install:
-    - pip install -U setuptools
-    - python bootstrap.py
-    - bin/buildout
+    - pip install zc.buildout
+    - buildout
+cache:
+  directories:
+    - eggs
 script:
     - bin/test -v1 -j99
 notifications: