TeamCity 2017.2 and Docker support

Hi,

That is nice to see a way to execute a build step inside a docker image... but it'll be better to make it possible to start a docker container at build step N and have it running up tp build step M, so it would be possible to execute more than one build step in the same container...

Nowadays (since TeamCity 9) we have a build template(s) where most of build steps get executed inside the same docker container (which is started almost at the beginning and stopped around the last build step). Unfortunately it is not possible to "migrate" to "native" Docker support for now :( Hope you can do the required support in next release(s) %)