This a major uplift with drastic changes to the Atmophere class that
will hopefully simplify the way files are read and handled.
Checking out on the major commit with modifications to the Atmosphere
grid class.
Commit to switch to master's.
Finished including and testing Doppler boosting.
Removed files located in Examples/Tests from tracking.
Added Example 3 to demonstrate the use of the new Doppler boosting
functionalities. Also sub-classing of Photometry into
Photometry_doppler in order to handle Doppler boosting at the high
user level.