Update Travis requirements for modern CMake

SoapGentoo · SoapGentoo · commit ba158fd22d00 · 2016-12-14T17:53:10.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -23,7 +23,10 @@ addons:
     sources:
     - ubuntu-toolchain-r-test
     - llvm-toolchain-precise-3.5
+    - george-edison55-precise-backports # cmake 3.2.3
     packages:
+    - cmake
+    - cmake-data
     - gcc-4.9
     - g++-4.9
     - clang-3.5
