adds:

• static string json output format @mr-tz
• test case invoking main @mr-tz
• tests via GH actions @mr-tz
• builds via GH actions, uploads to releases page @williballenthin
• pushed to pypi via GH actions @williballenthin

changes:

• package relative imports @b0urb0n
• register tests in setup.py @b0urb0n
• vivisect version @r0ny123
• code style via black, isort @mr-tz
• test files in sub repo @mr-tz

fixes:

• vivisect pyinstaller @williballenthin
• IDA 7.4+ support @Ana06
• strings algorithm via bytes @jedimasterbot

changes: v1.6.1...v1.7.0