Fixed an error in the finding of pending invites
Added test for the skill relationship, also removed some unused methods
Edited the initial data to have better names for users
Deleted all the unused methods from User
Fixed the naming of the tests to use better names
Fixed the naming of the skill tests and deleted an unused method
Fixed some naming and created and fixed some tests for Practical model
Fixed naming of some tests, also cleaned up the practical group tests
Added the functionality of an owner to practicalgroups, also renamed some properties and functions