provision/docker/docker: fixing ip tests and refactoring function return values

Also refactoring router and fixed its tests
provision/local/router_test: checking if error is nil in recording fs file opening
provision/docker/docker: created configurations for template and startup command

Also refactoring tests and added default to this configs in tsuru.conf
privisioner/docker: refactoring return values order

Also changing some ifs to occupy only one line.