Add gfortran package — required to compile SciPy

Fixes "dfftpack has Fortran sources but no Fortran compiler found"
error when SciPy is built on a machine without a Fortran compiler.
Remove positional and keyword arguments from call to super()
Remove *args and **kwds from signature of LEMONJuicerGUI.__init__()
Add 'db_path' keyword argument to LEMONJuicerGUI.__init__()
Add docstring to LEMONJuicerGUI.__init__()
LEMONJuicerGUI.open_db(): raise IOError if the LEMONdB does not exist
Add Bash completion for the 'juicer' command
Merge branch 'open-LEMONdB-from-command-line'
Pass to FITSFigure.__init__() the path to the FITS file
Register clean-up function to remove the mosaic FITS file
Use α and δ in calls to FITSFigure.show_markers()
Update docstring of FindingChartDialog.mark_closest_star()
Update docstring of FindingChartDialog.mark_star()
Display a coordinate grid
Merge branch 'show-ra-and-dec-in-chart'
Update Travis multiprocessing workaround