Merge pull request #9 from tbrinzer/master

Changes for CO_2 spectrum fitting
Add more flexibility for fitting spectra

Add the ability to specify center frequency, mu12^2, and phase as
additional fitting parameters.
Merge branch 'test_CO2_fitting'
bootstrap functionality

add an index for bootstrap sampling of the data
Merge pull request #3 from sgarrettroe/master

bootstrap and improved fitting changes