Fixes mode argument with --mode=genanswers

[cdrage]

When sudo atomic run projectatomic/helloapache --mode=genanswers is
supplied, the resulting error shows that --mode=genanswers is an
unrecognized argument.

This was introduced after refactoring the cli/main.py code to NOT include
uneeded parameters such as --provider-auth to CLI options such as init
and genanswers.

By adding self.parser.parse_known_args, this will ignore the added
--mode=genaswers to the CLI.

Fixes #792

[coveralls]

Coverage remained the same at 64.302% when pulling 39c3565 on cdrage:master into 0ebf267 on projectatomic:master.

[dustymabe]

instead of doing this why don't we just delete the --mode arg from args on line 482

[coveralls]

Coverage remained the same at 64.302% when pulling 30ab3b4 on cdrage:master into 0ebf267 on projectatomic:master.

[dustymabe]

without actually testing this out, i'll say that the code change LGTM. Charlie, do you mind running through some manual testing before you merge?

[coveralls]

Coverage remained the same at 64.302% when pulling 2e184ac on cdrage:master into 0ebf267 on projectatomic:master.

[cdrage]

#dotests

[cdrage]

@dustymabe sure, going to use init and genanswers to test this.

[cdrage]

@dustymabe init doesn't work, genanswers works fine.

INFO   :: - cli/main.py :: Atomic App: 0.6.2 - Mode: Init
DEBUG  :: - cli/main.py :: Final parsed cmdline: init projectatomic/helloapache -v --mode=init
ERROR  :: - cli/main.py :: [Errno 2] No such file or directory: '/tmp/nulecule-new-app-9rirsK/artifacts/docker/projectatomic/helloapache_run'
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/atomicapp-0.6.2-py2.7.egg/atomicapp/cli/main.py", line 106, in cli_init
    argdict['destination'])
  File "/usr/local/lib/python2.7/dist-packages/atomicapp-0.6.2-py2.7.egg/atomicapp/nulecule/main.py", line 183, in init
    with open(file_path, 'w') as f:
IOError: [Errno 2] No such file or directory: '/tmp/nulecule-new-app-9rirsK/artifacts/docker/projectatomic/helloapache_run'

is it because when using --mode genanswers will ignore the first argument? (in this case projectatomic/helloapache) and init does not?

[cdrage]

#dotests

[coveralls]

Coverage remained the same at 64.302% when pulling af728b3 on cdrage:master into 0ebf267 on projectatomic:master.

[cdrage]

OpenShift timed out ^^ ran locally and tests pass. Mergin'