pycrires v0.2.0

• Several routines for the calibration and detection of spatially-resolved sources have been included: remove_starlight, remove_systematics, and detection_map (thanks @ricolandman!)
• The obs_nodding_irregular method has been added for processing data with an irregular nodding scheme (thanks @ricolandman!)
• The obs_staring method has been added for processing data obtained in staring mode (thanks @DGonzalezPicos!)
• The extraction_required parameter has been added to the obs_nodding routines for faster processing
• The util module has been included for utility functions. For example,load_bt_settl_template fetches a BT-Settl spectrum that can be used with detection_map (thanks @ricolandman!)
• Many small improvements to the overall code and documentation