ENH : Draft of RCParmamDict

 This is a class for keeping track of default values.  It is a recursive
dictionary so we get some notion of namespaces.
ENH : Added draft of integrate_ROI
TST : added some tests for integrate_ROI
DEV: Updated spectroscopy.integrate_ROI based on comments in grp meeting

1) made function more general by removing references to energy
   replaced energy references with x-value references.
   energy --> x_value_array
   e_min --> x_min
   e_max --> x_max
2) added value check on x_value_array to make sure that the array
   increases in value, and if the array decreases in value, then
   the array is flipped to correct orientation. This check is followed
   by confirmation that values in x_value_array are equally spaced
3) updated documentation
BUG: Corrected test function name typos

Test functions for integrate_ROI were spelled intagrate.
Corrected spelling for both integrate_ROI test functions.
DEV: spectroscopy.py - Fixed Caswell's comments

1) Added array reversal for both counts and x_value_array in the event that
   the arrays are input running highest to lowest value in the independant
   variable array.
2) Removed the x_value_array spacing test which also resolves Tom's comment
   about not using exact float arithmetic for testing.
3) Added a value check on the x_min and x_max values so that in the event
   that the user assigns the maximum bounds to x_min and minimum bounds
   to x_max, the code corrects for this error automatically without
   raising an exception.
DEV: Added unittests for mods to spectroscopy.py

1) Added 2 tests to test_integrate_ROI_compute()
   a) Evaluate case where x_value_array, and compute are entered
      with monotonically decreasing x_array values
   b) Evalute case where all input parameters are entered "backwards"
2) Commented out unit test where all x_min and x_max values are flipped
   since a correction for this case has been added to the code resulting
   in this case NOT resulting in an exception error.
Merge pull request #3 from tacaswell/rc_params

ENH : Draft of RCParmamDict
DEV : configure travis
Merge pull request #12 from tacaswell/travis_config

Travis config
MNT: Added default value handling for the 'nx' parameter in 'bin_1D'
MNT: Added test for default value handling of bin_1d
BUG: Fixed bug in bin_1d testing method
DOC: Updated docstring on RCParamDict to be more verbose
DOC: Minor fix to bin_1d docstring
Merge pull request #15 from ericdill/rcparams_doc

DOC: Updated docstring on RCParamDict to be more verbose
Merge pull request #14 from ericdill/bin_1D

Added default value handling in bin_1d and a corresponding test
ENH/DOC: Updated keys_core and some docstrings in core.py
DOC : stub for wedge integration (caking)
MNT: Updated keys_core to include a 'units' entry for each key