Do not log a warning if colorama is not installed

[FlorianVeaux]

Fixes issue #:
#210

Description of the changes being introduced by the pull request:
Remove the warning

Please verify and check that the pull request fulfils the following
requirements:

• The code follows the Code Style Guidelines
• Tests have been added for the bug fix or new feature
• Docs have been added for the bug fix or new feature

More details available on the issue #210

Additional notes:
This PR doesn't fix the issue that the logger has not been initialized correctly. (Shows only on Python2 with No handler could be found ...). This would require a bit more knowledge of the library and an easy workaround for library users is to use logging.raiseExceptions = False

[coveralls]

Coverage remained the same at 98.712% when pulling e392647 on FlorianVeaux:master into 913beac on secure-systems-lab:master.

[trishankatdatadog]

LGTM

[lukpueh]

LGTM

[lukpueh]

Thanks pointing out these issues and providing a fix, @FlorianVeaux. We added the warning only recently (see #200). But you are right, a debug level message seems like a better fit. I'll merge this and follow up with a fix for the missing handler.