Release v0.2.0

What' new:

• Changes in logging: logging is now less heavy, more information is moved to debug;
• New --quiet option is added. It supresses all save warnings;
• ExecFlags (run configurations) in tests resources
• New plain-failed test reporter that prints only failed tests
• Save now prints the statistics of failed/passed tests, calculates pass-rate
• Refactoring and bugfixing