Version 6.1

Updates since release 7.0; The Pyut version goes from 6.0.0 to 6.1

• Update Python import to handle data classes and property annotations
• Fix export image and export pdf options; Non-functional in previous versions; Now platform independent and does not depend on any CLIs

Actual issues fixed

• 181 Fix runtests.sh
• 180 Fix IDFactory unit tests
• 179 Clean up unit tests after 3.8.5 update
• 178 Import Python Dataclasses
• 177 Additional tests for Python parser/visitor
• 176 Fix display fields option
• 175 Python Antlr Parser has bugs
• 174 Upgrade to Python 3.8.5
• 173 Rename PdfPosition to a more generic name
• 172 Pass DPI to plugin
• 170 Update Pyut Preferences
• 169 Platform Independent image generation
• 139 Fix PDF generation