wrap of elastic peak for lmfit, argument name in elastic_peak is changed
use consistent name in compton_peak function
write set_default function to wrap parameters for class
add doc for physics_model
add lmfit in yaml
clean up
add test for gauss model, and change output from physics functions as single output
add test for elastic model
add test for compton model
update setup.py file
add __init__ file
update on parameter_data
update compton test
use decimal 2
dict issue for python 3
clean up
new string type
add rst file
use helper function for doc
Merge pull request #131 from licode/lmfit_wrap

ENH : lmfit interface: wrap of elastic peak