Try to fix travis cmake.

Author: jgm

.travis.yml

@@ -13,6 +13,7 @@ addons:
     # we need a more recent cmake than travis/linux provides (at least 2.8.9):
     sources:
     - kubuntu-backports
+    - kalakris-cmake
     packages:
     - cmake
     - python3
@@ -23,19 +24,6 @@ before_install:
      then
          echo "Building without python3, to make sure that works."
      fi
- - |
-     if ( test "`uname -s`" = "Darwin" )
-     then
-       #cmake v2.8.12 is installed on the Mac workers now
-       #brew update
-       #brew install cmake
-       echo
-     else
-       #install a newer cmake since at this time Travis only has version 2.8.7
-       echo "yes" | sudo add-apt-repository ppa:kalakris/cmake
-       sudo apt-get update -qq
-       sudo apt-get install cmake
-     fi
 
 script:
  - make