YNPM blacklist for modules to exclude from installs

[paulgoldsmith]

There should exist a mechanism, perhaps using a JSON format file that can be specified as an argument to ynpm (and perhaps a property of yearn config), that can filter out one or more modules during the ynpm process.

ynpm-blacklist.json

{
    "modules": [
        "bower",
        "gulp"
    ]
}

[paulgoldsmith]

Two further comments/requirements:

• The ynpm logging should clearly present which modules have been excluded at the end of the output.
• When a module is excluded, the entire dependency tree below it should also be excluded.

[paulgoldsmith]

Optional: Blacklist strings could allow basic wildcarding

[paulgoldsmith]

Second Optional: Allow negative globbing of the above described wildcarding