Vendor colorama
Render logging output with colors if they are supported
Emit Log.error with a log level of ERROR
Add Log.deprecated which takes a removal version and logs a message

Deprecation message will use Log.warn if removal version is > 1
release away, otherwise it will use log.error
Use the new Log.deprecated to log the messages about mirrors
Split the version parsing into it's own function
Pass the environ dict into should_color
Add some tests to ensure behavior
Fix on Windows
Merge pull request #1109 from dstufft/better-warning-output

Colorize Log Output