OtherThreadsSniffer initial implementation
Added unit test for OtherThreadsSniffer
Use java 8 for unit tests
Register all thread local sniffers in a single set
Fixed logic of calculating the number of queries executed by other threads than current
Merge pull request #12 from bedrin/feature/other-threads-sniffer

Provide an API for validating the number of queries produced by other threads
Merge branch 'develop' into feature/callback-api
Added more verify methods to the callback api