v2.0.0: major release

Added:

• Personal Challenges
• Periodic PointConcept
• Periodical Classification

v0.9: new release

* core 0.9
* web 0.5
* test 0.4

v0.8: new release

* core 0.8
* web 0.4
* test 0.3

v0.7.1: minor release:

* core 0.7.1
* web 0.3
* test 0.2.1

v0.7: minor release

* core 0.7
* web 0.2
* test 0.2