Add ProjectWideDependencyChecker check API

[stefanpenner]

Add ProjectWideDependencyChecker check API

This allows someone to make broader assertions against the project’s dependencies. The goal here is to handle the complexity of making these assertions here in ember-cli-version-checker.

• no extra disk IO, all addon lookup goes through ember-cli's public APIs and ensures to only utilizes pathways that use ember-cli's authentication
• good default errors
• provides a layered API that allows the end user to run checks, but constraint their own rollup if needed.

Example:

const checker VersionChecker.forProject(project);

checker.check({
  ‘ember-data’: ‘>= 3.16.0’,
  ‘ember-resolver’: ‘*’,
}) === {
  /* typically what people want */
  isSatisfied: true | false,
  message: ‘’ || ‘useful canned error message’,
  
 /* checker.check(...).assert() will throw a canned error response */

 /* checker.check(...).assert(description) will throw a canned error response but with a custom description */
  assert(description?) { } 

  /* deeper details for power users*/
  node_modules: {
   ‘ember-data’: {
     isSatisfied: true | false,
     message: ‘’ || ‘useful canned error message’,
     versions: [/* list of versions found */]
   }, 
   ‘ember-resolver': { /* basically same as ember-datas blob, but for the results of ember-resolver */ },
  }
}

This Commit also fixes/cleans up the testing infrastructure to simplify the testing of the above new feature

---

TODO:

• Update readme
• ensure this meets our needs etc
• add missing unit test for filterAddonsByNames for good measure

[scalvert]

Just a few small changes, but otherwise looks good!

[rwjblue]

Only minor tweaks, LGTM

[stefanpenner]

released as v5.1.0 🎉