Fix bug for valid-but-empty XML dependency file.

[Fixes #72784198]
Add support for custom gradle invocation.

* Add more in-depth README section about gradle integration.

[Finishes #68891294]
Upgrade rspec to ~> 3 and fix specs to match.
Fix feature spec to reflect new default configuration.

[#68891294]
Bump version to 1.1.0
Fix floating in html report for dependencies with no desciption.

[Fixes #72476388]
When an NPM package misdeclared its "licenses" as a Hash (and not an array of hashes), deal with it. :sunglasses:

For example, see grunt-concurrent v0.5.0.

Fixes #108.
Merge pull request #109 from flavorjones/issue-108_misdeclared-licenses

When an NPM package misdeclared its "licenses" as a Hash, deal with it.
Bump to 1.1.1.
Improving commandline error messages in feature tests.
Extracting the check for Appleness into the Platform class.
Checking for external dev dependencies before running tests.
Merge branch 'external-dependency-check'
Using https in the Gemfile.
Adding jruby in 2.0 mode to the travis suite.
Using Kernel#` instead of capture3

because it appears to be broken on JRuby.
Looks like travis doesn't support jruby in 2.0 mode yet.

See https://github.com/travis-ci/travis-ci/issues/2432
Removing the Java and JRuby opts

in the hope that this will make the jruby tests less flaky.
Adding gradle as a dev dependency.
Reverting use of #open3

because JRuby.