0.6.2: SchemaModel and synthesis bugfixes

New Feature

• Add SchemaModel column name access through class attributes (#388) @jespercodes @jeffzi 🎉
• Parametrized PandasExtensionType types (#389) @jeffzi 🎉
• adding filter argument to strict parameter (#401) @ktroutman
• feature/341: improve str and repr methods for schemas (#413)

Bugfixes

• fix py3.6 optional + literal dtypes in SchemaModel (#379) @jeffzi 🎉
• Fix minimally required packaging version (#380) contribution #1️⃣ @probberechts 🎉
• prevent mypy Check getattr error for registered checks 920a98c
• Compatibility with numpy 1.20 (#395) @jeffzi
• dataframe strategies can generate regex columns (#402)
• bugfix: df data synthesis with size=None, fix CI (#410)
• bugfix: SeriesSchema raises SchemaErrors on lazy validation (#412)

Repo Improvements

• improvements to local CI (#409) @jeffzi
• feature/414: improve contributing docs and add to sphinx docs (#416)