fixed histogram problem for gluons
updated test.py file to fill histos correctly(?) for all particles. Code needs to be cleaned up, organized, and updated based on Burt's comments on github.
attempted to clean up code from test.py; still needs modification b/c code is spitting errors
first attempt at creating opening angle plots; not sure what arguement to give CosTheta function
histograms should be fixed...no longer seeing uniform distributions; code needs cleaning, but that's being done in modtest.py, made some slight changes here as per suggestions from file_loops pull request