Ubuntu 14 fix

docs/install.md

@@ -19,6 +19,7 @@ sudo make install
 sudo add-apt-repository ppa:ubuntu-toolchain-r/test
 sudo apt-get update
 sudo apt-get install g++-4.9
+sudo apt-get remove g++-4.8
 sudo apt-get install pkg-config libboost-system1.55-dev libboost-thread1.55-dev libboost-filesystem1.55-dev libboost-log1.55-dev libgtkmm-3.0-dev libgtksourceviewmm-3.0-dev aspell-en libaspell-dev git
 ```
 ```sh