Merge branch 'BUG_FIX_estimate_elastic_scattering_threshold' into 0.7.1
Merge branch 'BUG_FIX_fourier_ratio_single_spectrum' into 0.7.1
Merge branch 'ENH_spikes_removal_tool_update' into 0.7.1
Merge branch 'BUG_FIX_second_pointer' into 0.7.1
Modify drawing.utils.plot_spectra: support for specifiying a subplot

Currently only works for cascade, but should be easy to make for some
of the other styles.
Modify drawing.utils.plot_spectra: add ax-parameter for 'overlap'

Also add a sentence in ax-parameter docstring
Merge branch 'master' into ENH_plot_spectra_specify_ax
Merge branch 'master' into 0.7.1
TESTS: energy units
Automatic style corrections courtesy of autopep8
TESTS: FWHM test
Merge pull request #328 from pburdet/TEST_get_energy_xray_line

Test energy units
Add missing dm_4D_data folders to setup.py
Merge pull request #329 from francisco-dlp/BUG_FIX_missing_folder_in_setup

Add missing dm_4D_data folders to setup.py
Remove invalid dm 4D tests
Merge pull request #330 from francisco-dlp/Remove_dm_4D

Remove invalid dm 4D tests
Update changes
RELEASE 0.7.1
Release back to dev
Fix indexing header