Don't import rules with a conflicting definition. (#84)
Don't import rules with a conflicting definition. (#84)

This avoids manual `excludes=[]` and `overrides={}`, which were suggested in the linked issues.  We exclude things that have already been imported, so to override them, simply import them before `docker_repositories()` and the exclusion logic will handle the rest.

Fixes: https://github.com/bazelbuild/rules_docker/issues/55
Fixes: https://github.com/bazelbuild/rules_docker/issues/77
bazelbuild/rules_docker,bazelbuild/rules_docker,bazelbuild/rules_docker,bazelbuild/rules_docker