Testing framework

[OrMemphis]

Currently we use only Go's testing, but we rely on running a docker container that runs Memphis in the background.

we need to either mock Memphis or introduce a testing framework that allows us to control the container.

[elchinmemphis]

As one option - I believe in that Testcontainers can be utilized for this purpose: testing integration parts

[g41797]

After review, merge and test of #140 may be closed as implemented