version 0.5
- improved dnf parsing: more complex if statements are parsed as dnf, 
- complex if statements were failing with simplify_conditional: issue #13

version 0.4.7
- Fix for issue 12, Thanks to Sander Scholtus: substitute_values was failing on conditional statements.

version 0.4.6
- Fix for issue 11, Thanks to Ton de Waal: simplify_conditional was not working
correctly on pure categorical rules
- output of detect_boundary_cat has changed (improved)

version 0.4.4
- Negative coeficients in linear rules were ignored, now fixed

version 0.4.3
- Fixed issue #9, bug with pure categorical rules.

version 0.4.2
- Internal updates for compatability with 'validate' version 0.2.3.

version 0.4.1
- initial release

