Synopackage docker image tags

The synopackage docker images are tagged in the way described below

• "latest" is the latest version from master branch. It might be unstable or even doesn't work. Most likely it is version prepared for testing purposes
• "x.y.z" where x,y,z are numbers (i.e. "0.4.7"). This tag which was most likely deployed to synopackage.com.
• other, like "dotnet31", "angular8_latest", are used for test purposes only. Mostly there are some breaking changes in there and need to be tested before it will run on production.