test commit
Issue #90 - Initial support towards plugin manager

The initial implementation of plugin manager class is done which now supports
listing installed plugins and available plugins.
Issue #90 - Install plugins

* A plugin can be installed with a simple method
* Jenkins can be queried to check whether a restart is required for the
completion of plugin installation
Issue #90 - If you give valid tree the response is not empty
Issue #90 - Plugin support updates

list_available and list_installed will now return a pure hash with keys as
plugin names and values as plugin versions. This will easy to traverse through
the plugins. The documentation example is also updated to reflect this change
Issue #90 - List the plugins by criteria
Issue #90 - Uninstall given plugins using PluginManager
Issue #90 - Updates to PluginManager

* restart_required? will also check if restart is required for plugin uninstallations.
* list_installed will not optionally accept a parameter to skip bundled plugins
Issues #90 - Listing available updates and installing plugin updates
Improvement to exception message printing

Exception classes will use the given messages as it is and add its own generic
error message only if no message is passed in
Issue #90 - Initial addition of enable/disable
Issue #90 - Improved list_installed method
Issue #90 - Initial addition of unit tests
Issue #90 - Added missing unit tests for plugins
Issue #90 - Initial addition of func tests for plugin
Issue #90 - PluginManager testing updates

* Added functional tests for plugin installs and uninstalls
* Fixed unit tests not to check for return code for installs and uninstalls
Issue #90 - Functional spec updates
remove / prepended to api_get_request from the list method in View class
Issue #90 - More updates to PluginManager

* Added PluginNotFound exception
* The list_installed will now accept an optional filter - this will also be an enhancement to the list_by_criteria method
* Added a get_installed_info method that obtains the information about a particular installed plugin
Issue #90 - More updates to PluginManager

* Method 'downgrade' added to downgrade plugins
* Method 'check_for_updates' added to check for available updates
* Method 'unpin' added to unpin specified plugins
* Documented the rest