Merge pull request #2 from mindscratch/master

add command to list available versions of go to be installed
gobrew was not inserting workspace into path on init
Merge pull request #4 from mindscratch/master

add ability to customzie the URL where go install files are downloaded from
Merge branch 'dev'
updated screeenshot
fixed gobrew list command to list all available versions instead of just the current versions