Update to rain v0.7.1 to bring in formatting improvements

Add verify flag and improve object ordering

Move format and parse packages into github.com/aws-cloudformation/rain

Add compact output flag

Fix snapcraft build

Moved the command to its own folder for better compatability

Add go module configuration

Added support for reading from stdin

Removed dependency on goformation, fixed some bugs, and made verifica…

…tion happen by default

Fix a few bugs, improve testing, and add snap support