Merge pull request #15 from s-pearce/vel

Adds velocity_funcs, updates adcp_funcs, .gitignore a tmp/ directory
Corrected referencing/assignment errors
Merge pull request #16 from cwingard/adcp

ADCP
Starting creation of PHSEN functions
Continued development of pH function and test function
Adding pCO2 functions, part of Sunburst SAMI-II family of instruments
begin velocity functions unit tests
Merge branch 'master' into vel
Finalized pH functions and starting on test functions for PCO2
Finalized PCO2 functions and test case. Minor edits to pH test remain.
Finalized CO2 and pH functions, with basic housekeeping on other functions.
Correcting test functions and generic_functions
Merge pull request #17 from cwingard/pH

CO2 and pH Functions
Merge branch 'master' into vel

Conflicts:
	ion_functions/data/test/test_generic_functions.py

fixed pull request 17 merge conflicts, and updated
Re-wrapped the vel functions.  Fixed test_vel filename.  Other fixes.