adding RooFit examples
updating configs for new fit variables
Added mutli-var fitting and tests, removed obsoletes
added functions adjust_overflow_to_limit & clean_control_region
added get_best_max_y and get_best_min_y functions to tools/plotting.py
 - updated fitting and plotting scripts for the new fit variables
 - added closure test and closure test type options to fitting script
 - added no_combined_signal option to fitting script
 - added test option to fitting script (just central measurement)
 - added disable-constraints option to fitting script
more control plots for the fit variables
moved closure test definitions here, addded JSON read functions for fit results
added commands to run & plot the fit checks
Making everything tidy after so many pull requests
updated analysis commands
Merge pull request #95 from kreczko/roofit_examples

adding RooFit examples
Merge pull request #97 from kreczko/cleaning

Making everything tidy after so many pull requests
fixed commands to plot the fit checks
fixes according to feedback
Merge pull request #96 from kreczko/multi_variable_fitting_2nd

Multi variable fitting
replaced travis script with ci/test.sh
replaced travis install
enabled apt cache & set python packages to system instead of virtual python
making everything tidy & up-to-date
 - updated ci/test.sh with the latest tests (rebase) after merging #96
 - removed obsolete stuff from ci/install.sh
 - now installing numpy and cython instead of compiling it (speedup!)