First steps in doing XY8 scheme decoupling update
Implemented XY8 decoupling and updated combine to sequence function

XY8 decoupling elements created, if timing is right still needs to be
tested.
New sequence function also needs to be tested.
Still to do is a loop over different tau’s
XY8 Decoupling and sequencer bug fixes
All is working, only need to double check timing of elements
Fixed Timing Issues with XY8 and XY4 decoupling
Loopable over time series
Added append_element function to pulsar sequence
made DynamicalDecoupling.py work with different times
Merge branch 'XY8-Decoupling-Development'