Add list of version builds to readme

Author: impactmass

README.md

@@ -2,6 +2,19 @@
 
 [![Circle CI](https://circleci.com/gh/reactioncommerce/base/tree/master.svg?style=svg)](https://circleci.com/gh/reactioncommerce/base/tree/master)
 
+With the release of Meteor 1.7, we changed the versioning of this repo and it's Docker builds to align with Meteor's release. Henceforth, releases in this repo will be tied to the corresponding Meteor release.
+
+Current version builds:
+
+| reactioncommerce/base version       | Meteor version  |
+| :----------------------------------:|:---------------:|
+| v1.7.0.1-meteor                     | v1.7.0.1        |
+| v1.7-meteor                         | v1.7            |
+| v1.6.1-meteor                       | v1.6.1          |
+| v4.0.2                              | v1.6.1          |
+
+See [Docker Hub](https://hub.docker.com/r/reactioncommerce/base/tags/) for full list.
+
 ### Build
 
 Add the following to a `Dockerfile` in the root of your Reaction Commerce project: