warnings when incorrect parameters are given

[lachlangrose]

import os
import hjson
from map2loop.project import Project
proj = Project( 
                 loopdata_state = "WA",)
)                

proj.update_config(
                    out_dir='./gmdpaper-faultslip',
                    bbox_3d=bbox_3d,
                    proj_crs={'init': 'EPSG:28350'},
                    overwrite='true',
                  )

If overwrite is set to a boolean type, True it does not work. It should at least tell the user its the wrong type, considering the logical type for this parameter is a boolean

[yohanderose]

Users can now pass a bool to overwrite, printing a warning. If true, we convert to the string 'true'. If False, we warn and call the typical overwrite catch which is now a function c71cadf