Features
 - Add `--version` and `--pyse_version` to the command line interface (cli).
    Tip: use `pip freeze` for version information on all installed packages.
 - Allow for using both dashes and underscores in multi-word cli arguments (before only underscores were allowed). Example: `--db_overwrite` and `--db-overwrite` are now both valid.

Fixes
 - Use PySE v0.7.0, which fixes some sources having incorrect values when using `--force_beam`
 - Fixed issue where the wrong (ns/ew)_sys_err was used when force fitting null detections
 - Do not use forced null detection values when calculating variability metrics

Misc
 - Removed `sigma_rms_min` and `sigma_rms_max` from varmatric table.