Command line message ends up in generated RAML file

[schuderer]

• ML Launchpad version: 1.0.0

Description

When generating a raml file, using an abbreviation of the command generate-raml adds the line "Command g matches generate-raml" to the beginning of the generated RAML.

Steps to reproduce

$ cd examples
$ mllaunchpad -c tree_cfg.yml g petals >temp.raml
# ...
$ head temp.raml
Command g matches generate-raml

#%RAML 0.8
---
title: Put title of your iris API here
baseUri: https://{host}/iris/{version}
version: v0  # new version only for API-breaking updates
...

Should be a simple question of outputting this message to stderr instead of stdout.

[schuderer]

Also changed test_cli.test_generate_raml to catch this regression (it should have caught it earlier, but did not).