[PYTHON] Virtualenvwrapper for python 3

Install Virtualenvwrapper

$ [sudo -H] pip[3] install virtualenvwrapper

Create virtualenv home directory

$ mkdir ~/.virtualenvs

Setup work and project directory in ~/.bashrc

export WORKON_HOME=$HOME/.virtualenvs    
export PROJECT_HOME=$HOME/[PROJECT_FOLDER]
source /usr/local/bin/virtualenvwrapper.sh

Add mkvirtualenv aliases

alias mkvenv3='mkvirtualenv --python=/usr/bin/python3 '
alias mkvenv3.1='mkvirtualenv --python=/usr/bin/python3.1 '
alias mkvenv3.2='mkvirtualenv --python=/usr/bin/python3.2 '
alias mkvenv3.3='mkvirtualenv --python=/usr/bin/python3.3 '
alias mkvenv3.4='mkvirtualenv --python=/usr/bin/python3.4 '

Note : python3 should point to the latest python installed, here python3.5 that's why we add aliases for each previous python3 versions.