WIP: Save output diffraction intensities into .chi, .dat .gsas or .xye file formats.
STY: style fixed -PEP8
DOC: modified the documentation in create_filepath
ENH: changes after the comments, change  create_filepath to _valid_inputs
ENH: changed the function to _format_output_path
ENH: added check if the output file already exists and only blow it away if explicitly asked to
ENH: two functions one to validate the inputs and other to create a file path to save output intensities
ENH: changes according to the comments
TST: added the tests to save_output
API: removed due to api change
ENH: removed the save_gsas to create it in another PR
TST: modified the test for output_save

Conflicts:
	skxray/tests/test_io/test_powder_output.py
DOC: added a GSAS reader from GSAS-II
ENH: changes to the GSAS reader to use in ourlibrary
TST: modified the test
ENH: deleted gsas files and save_gsas from the save_powder_output.py. Adding a gsas reader and
writing gsas readeble files in seperate PR
TST: modified the tests for save_output
STY: remove the extra spaces and checked with PEP8