modificatons for multi-time scale methods, adding gam,gwr,kriging options for daily deviation surfaces

first modifications to add interpolation methods and covaratiates options for daily deviation surfaces

Merge branch 'bp/interp' of code.nceas.ucsb.edu:environmental-layers into bp/interp

analyses for multi-time scale paper, monthly hold-out proportions (0-70%) for all methods

modifications, contribution of covariates, figures and analyses for paper 1, OR

running gwr CAI with 40-70% monthly hold out for multi-time scale paper, OR

running gwr fusion, 40-70% monthly hold out for multi-time scale paper, OR

running gwr fusion, 0-30% holdout for multi-time scale paper, OR

Merge branch 'bp/interp' of code.nceas.ucsb.edu:environmental-layers into bp/interp

Adding modis_LST_mean.py. Python alternative to grass version. Outputs geotif or flt.