v2.0 - filtering support, focus support, equality messages

I'm happy to announce a new major release of Expecto. This release contains many improvements for great good!

This release was made possible through the work of the following people.

• @cloudRoutine – initial work towards .Net core
• @MecuSorin – support focusing on tests during development by prefixing f, like ftestCase
• @Krzysztof-Cieslak – better diff messages for string
• @Krzysztof-Cieslak – support for listing tests and filtering them via test parameters
• @fbehrens – documentation improvements

Cred to you guys!

Henrik