0.5.0

• Add support for listing and installing unstable versions
• Prevent bugs in config files without final newline
• Ensure the modified PATH is exported on bash and zsh
• Prevent multiple selection of the same shell in g-install
• Improve the --quiet modifier
• Normalize messages styles and wording
• Support double-dash to signal end-of-params
• Tweak README file
• Offer to install latest go version after installing g
• Install requested version when g run cannot find it. See #3
• Warn about installing on a non-default path. See #5
• Add goenv to the alternatives list on README
• Add instructions for removal on README
• Make the detection of previously installed g stricter