Move to the API provided by UPM 2.x.

[Sergey Podobry]

New API eliminates the possibility of "The current license status cannot be retrieved because the Plugin License Storage plugin is unavailable." errors. Also it makes jar-file smaller.

References:

• https://answers.atlassian.com/questions/269870/cannot-squash-classnotfoundexception-thirdpartypluginlicensestoragemanagerimpl
• https://answers.atlassian.com/questions/315037/pluginlicensestoragepluginunresolvedexception-error
• https://bitbucket.org/atlassian_tutorial/tutorial-licensing/overview

[Sergey Podobry]

Fixed in 1.0.10 and 1.1.7.