Script: gcc-4.9 installer removed

scripts/install_gcc.sh

-# please refer to this discussion
-# https://gist.github.com/ibogun/ec0a4005c25df57a1b9d
-sudo apt-get install python-software-properties
-sudo add-apt-repository ppa:ubuntu-toolchain-r/test
-sudo apt-get update
-sudo apt-get install gcc-4.9
-sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.9 50
-sudo apt-get install g++-4.9
-sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.9 50