Intent: Implement numpy functions within eppy in Python to provide functionality in 	environments where numpy is not available. Branch: i30_pythongeometry --------------------------------------------------------------------------------------- *eppy/geometry/height_surface.py* *eppy/geometry/surface.py* -Added a try/except statement to import py_numeric when numpy is not available... -Replaced square root & arc-cosine functions from numpy with native Python math  functions...
Intent: Implement numpy functions within eppy in Python to provide functionality in
	environments where numpy is not available.
Branch: i30_pythongeometry
---------------------------------------------------------------------------------------
*eppy/geometry/height_surface.py*
*eppy/geometry/surface.py*
-Added a try/except statement to import py_numeric when numpy is not available...
-Replaced square root & arc-cosine functions from numpy with native Python math
 functions...

*eppy/geometry/plan.md*
-Updated the plan and described alternatives to creating a new function for the
 last two functions...

*eppy/geometry/py_numeric.py*
-Refactored code to conform to PEP8 standards...

-Ran py.test for test_py_numeric.py module: All passed.

jamiebull1/eppy,jamiebull1/eppy,eayoungs/eppy,eayoungs/eppy,santoshphilip/eppy,santoshphilip/eppy,eayoungs/eppy,jamiebull1/eppy,santoshphilip/eppy