Added support of passing options for berkshelf via knife.rb

[iavael]

No description provided.

[tmatilai]

Thanks! I think the idea itself is fine. But this breaks compatibility with Berkshelf 2 which is still widely used. Tests and documentation would also be nice. =)

Travis tests seem to be broken, but that feels to be related to a new net-ssh version.

[iavael]

But this breaks compatibility with Berkshelf 2

According to d8227f7 berkshelf 3+ is required

documentation would also be nice.

I'll update wiki as soon as this PR would be accepted. Plan to add

• You can control berkshelf groups with knife[:berkshelf_options][:except] and knife[:berkshelf_options][:only] options (type of Array)

in the end of https://github.com/matschaffer/knife-solo/wiki/Berkshelf-&-Librarian-Chef-integration#berkshelf-integration

[tmatilai]

@iavael the tests use Berkshelf 3, but knife-solo itself is also compatible with v2 (see #268).

[matschaffer]

Didn't realize you'd added a compatibility check. Thanks!

What's the reason for the defined?(::Berkshelf) check here? Seems like if it failed the original code as well as line 26 here will fail as well.

[iavael]

Well, you are right, there is no reason. I removed it.

[coveralls]

Coverage decreased (-0.04%) to 89.91% when pulling 5f1049e on iavael:feature/berkshelf-options into 0b181fb on matschaffer:master.

[matschaffer]

Thanks!