Redmine Java API 1.14 and 1.15: support for invalid SSL certificates

Redmine Java API 1.14 brings support for invalid SSL certificates. Before this, the API would refuse to work with servers using self-signed certificates (which seems to be the absolute majority of all the SSL certificates in the world).

Details: https://github.com/taskadapter/redmine-java-api/issues?milestone=5

Version 1.15 does not have any new functionality, but supports a newer JSon library. See https://github.com/taskadapter/redmine-java-api/issues/47 for details.

The next Task Adapter version (2.1) will use the latest Redmine Java API 1.15.