Adds environment setup script to installation.

Author: scottpurdy

build_system/post_build/files_to_copy.txt

@@ -68,6 +68,7 @@ run_tests.sh bin/run_tests.sh
 external/licenses               share/doc/licenses
 conf/default/nupic-default.xml  conf/default/nupic-default.xml
 conf/default/nupic-logging.conf conf/default/nupic-logging.conf
+env.sh                          env.sh
 
 # Python API and regions