Plugin

This is the interfacing class represents the API that we intend to provide the plugins to use.

For plugins to be independent of the Bundler internals they shall limit their interactions to methods of this class only. This will save them from breaking when some internal change.

Currently we are delegating the methods defined in Bundler class to itself. So, this class acts as a buffer.

If there is some change in the Bundler class that is incompatible to its previous behavior or if otherwise desired, we can reimplement(or implement) the method to preserve compatibility.

To use this, either the class can inherit this class or use it directly. For example of both types of use, refer the file `spec/plugins/command.rb`

To use it without inheriting, you will have to create an object of this to use the functions (except for declaration functions like command, source, and hooks).

SourceList object to be used while parsing the Gemfile, setting the approptiate options to be used with Source classes for plugin installation

Manages which plugins are installed and their sources. This also is supposed to map which plugin does what (currently the features are not implemented so this class is now a stub class).

Handles the installation of plugin in appropriate directories.

This class is supposed to be wrapper over the existing gem installation infra but currently it itself handles everything as the Source’s subclasses (e.g. Source::RubyGems) are heavily dependent on the Gemfile.