Update scripts that help install a virtual environment

Author: mdmintz

virtualenv_install.bat

@@ -3,7 +3,8 @@
 :: virtualenv commands such as "mkvirtualenv [ENV_NAME]"
 :: for creating and using Python virtual environments.
 
-python -m pip install --upgrade virtualenvwrapper-win
+python -m pip install --upgrade pip
+python -m pip install virtualenvwrapper-win --force-reinstall
 echo:
 echo:
 echo: *** You may now use virtualenv commands in your command shell. ***

virtualenv_install.sh

@@ -7,8 +7,8 @@
 [[ $0 != "$BASH_SOURCE" ]] && sourced=1 || sourced=0
 if [ $sourced = 1 ]
 then
-  python -m pip install --upgrade virtualenv
-  python -m pip install --upgrade virtualenvwrapper
+  python -m pip install --upgrade pip
+  python -m pip install virtualenvwrapper --force-reinstall
   export WORKON_HOME=$HOME/.virtualenvs
   source `which virtualenvwrapper.sh`
   echo ""