Dockerfile: update to Ruby 2.7, bundler 2.2.1 and re-add --nodocs to microdnf
Dockerfile: update to Ruby 2.7, bundler 2.2.1 and re-add --nodocs to microdnf

DanielRussell/echo-api,3scale/echo-api,3scale/echo-api,mayorova/echo-api,mayorova/echo-api