first small edits
turning some functions to internal, and making sure that these functions return astropy Quantities.
made the true obliquity an astropy Angle Quantity
more edits to differential rotation
implementing astropy units in the rotation code
first working rot_hpc using existing wcs transformation code
improving the documentation
adding in tests

adding in tests
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