Forte Release v0.2.0

• Add functionalities to data augmentation (#532, #536, #543, #554, #619, #685, #717)
• Fix issues in examples and create some new ones (#545, #624, #529, #632, #708, #711)
• Improve doctoring and refactor documentation (#611, #633, #636, #642, #652, #653, #657, #668, #674, #686, #682, #723, #730, #724)
• Add audio support to DataPack (#585, #592, #600, #603, #609)
• Improve and fix issues in ontology system (#568, #575, #577, #521)
• Relax package requirements and move out dependencies (#705, #706, #707, #720, #760)
• Add readers and selectors (#535, #516, #539)
• Create some utilities for pipeline (#499, #690, #562)
• Provide more operations for DataPack and MultiPack (#531, #534, #555, #564, #553, #576)
• Several clean up and bug fixes (#541, #693, #695)