merge two before_install sections

.travis.yml

@@ -12,6 +12,9 @@ before_install:
   - wget -O ~/bin/OmegaPlus "https://www.dropbox.com/s/m9ppejh6qz0eqmy/OmegaPlus?dl=1"
   - wget -O ~/bin/seq-gen "https://www.dropbox.com/s/el8375o09snd5v5/seq-gen?dl=1"
   - chmod +x ~/bin/*
+  # Set CXX1X for R-devel, as R-devel does currently not detect CXX1X support for gcc 4.6.3
+  # Check if we can remove this at some point in 2017
+  - if [[ "$TRAVIS_R_VERSION_STRING" = 'devel' ]]; then mkdir ~/.R && echo 'CXX1X=g++ -std=c++0x -g -O2 -fPIC' > ~/.R/Makevars; fi
 
 r_packages:
   - lintr
@@ -23,8 +26,3 @@ after_success:
 
 notifications:
   email: false
-
-# Set CXX1X for R-devel, as R-devel does currently not detect CXX1X support for gcc 4.6.3
-# Check if we can remove this at some point in 2017
-before_install:
-- if [[ "$TRAVIS_R_VERSION_STRING" = 'devel' ]]; then mkdir ~/.R && echo 'CXX1X=g++ -std=c++0x -g -O2 -fPIC' > ~/.R/Makevars; fi