Add step generator and test for ForwardTimeScheme, rename step generators
Remove untested code from TimeScheme.integrate
Remove broken setup, add test for integratE
Move all methods to inside class, fix integrate test, add some code for integrate (still fails)
Add failing test for currentT
Add implementation of currentT
Add failing tests for scheme storing X
Add code to store current x position
Change currentValue to currentU
Change tests to expect a state vector [u, x, t]
Add test to initialise scheme with state vector
Fix some tests, check_nextTimeStep still broken
Fix tests
Add some debug printing to tests
ForwardTimeStep: nextTimeStep test passes, integrate fails
Add implementation of BackwardTimeScheme
Add failing tests for CentredTimeScheme
Change array equality tests to take floating point precision into account
Implment CentredTimeScheme