creating a mapcube solar derotation function
added in a function to test if the input is an astropy pixel Quantity, as this function is explicitly used in many different functions.
small change
small changes
replaced pixel testing function and added arcsec testing function
add in the rotation function
pulled out the solar differential rotation function
expanding tests
adding in notes
re-wrote the creation of the new, shifted mapcube.  Tests for applying shifts
fixed first working mapcube solar derotate
fix to apply shifts to get the right data clipped; still need to fix positioning information
removed prints used in debugging
adding in test code for solar derotate
adding in test code for solar derotate
tests for solar differential of mapcubes
fixed tests to properly count the number of maps
removed position.py - this code functionality is now the function '_sun_pos' in /physics/transforms/differential_rotation.py
removed unnecessary import of matplotlib