Fine tuning travis linux settings

.travis.yml

@@ -18,8 +18,6 @@ notifications:
    on_failure: always
 
 install:
-  - CMAKE_VERSION_MM=3.2
-  - CMAKE_VERSION_FULL=$CMAKE_VERSION_MM.2
   - git clone https://github.com/HowardHinnant/date
   - cd date
   - git checkout tags/v1.0.0
@@ -29,9 +27,8 @@ install:
       && sudo add-apt-repository -y ppa:apokluda/boost1.53
       && sudo add-apt-repository -y ppa:george-edison55/cmake-3.x
       && sudo apt-get update -qq
-      && sudo apt-get update -qq
+      && sudo apt-get upgrade -qq -y
       && sudo apt-get install -qq g++-4.8 libboost1.53-dev --no-install-recommends
-      && sudo apt-get install -qq -y g++-4.9 cmake cmake-data
       ;
     fi