Python-evtx

i will never ever remember to update the version, so sorry.

changes:
- bump version to v0.7.4

changes:
- relax dependencies for most users 72 chapinb

fixes:
- version number

adds:
- show records by date filter scherma

fixes:
- handling of invalid dates 43
- handling of malformed evtx files
- pin dependencies due to py2 deprecation 67 atcuno
- testing on pytest 4 mcepl

lots of enhancements to improve code quality:
- unit tests! also, travis integration with github project.
- remove hacky python string templating solution to dealing with substitutions.
- add `.xml()` and `.lxml()` to records.
- lots of fixes to bring code in-line with pep8 and style guide.
- fix a bunch of bugs due to bad data/encodings.
- add support for CharacterReferenceNode