v0.1.16

This release brings a major new feature: pluggable policy sources (which addresses the feature request in #131)

• Along with the ability to source policy (rego files) from git, opal 0.1.16 adds the options to serve policy files into opal from an external API that serve tar bundles.
• the format of such files is the same as OPA bundles
• We added a document explaining how Sourcing policy from API works
• We added an example docker compose configuration with policy sourced from API instead of git.
• Major props to @obsd - our newest addition to the OPAL team - for the launch of his first feature :)

This release also adds few minor fixes and improvement:

• #161 is fixed: we added the healthcheck policy to the manifest, so OPA healthcheck policy should work in kubernetes just fine :)
• We increased the log verbosity to make it more clear how messages are routed within OPAL.