Added note on deployment of new impact functions
Wrote sections on deploying impact functions and also the use of assign_hazard_values_to_exposure_data towards issues #487
Added beginnings of tutorial impact function for raster hazard and vector exposure
Updated docs with new example impact function
Update script for pushing realtime impact report to only push specific report.
Merge remote-tracking branch 'origin/master'
use 'affected' instead 'FLOODPRONE', but 'FLOODPRONE' still works if no 'affected' attributes ##520
add depth threshold for #521 and pep8.
Resolved merge conflicts with master