Bump version for the 2.1 release.
Bump version for the 2.1 release.

GateNLP/gateplugin-LearningFramework,GateNLP/gateplugin-LearningFramework,GateNLP/gateplugin-LearningFramework,GateNLP/gateplugin-LearningFramework,GateNLP/gateplugin-LearningFramework