Expecto 2.0.0

Release Notes: * [infra] v2.0.0 * Merge pull request #14 from Krzysztof-Cieslak/filter * Implement filtering * Merge pull request #13 from Krzysztof-Cieslak/list_tests * Add tests for `--list-tests` * Add config for VSCode buliding and debugging * Fix arguments * List tests * Merge pull request #4 from cloudRoutine/configuration * add facade rename to build * Merge pull request #11 from Krzysztof-Cieslak/string_error * Fix breaking changes * Add tests for string comparison * Add string comparison * Merge pull request #12 from fbehrens/patch-1 * update simplest irb use in readme * Merge pull request #9 from MecuSorin/master * [tests] Fixed some cosmetic issues * [expecto][tests] Added focusing support for computation tests * [expecto][tests] Added focus and pending behavior * added appveyor config * setup FAKE build for netframework and netcore * netcore fsproj and net46 build success * netframework building successfully * expecto netcore fsproj * netcore expecto savepoint * fix logging remove missing files * started devguide * upgrade to paket4, setup sln, setup FAKE build * Update README.md * [docs] improve readme