Update README

Author: carloslopes

README.md

@@ -1,2 +1,30 @@
-# docker-ci-python
-Dockerfiles used to generate containers used by our CI 
+# Codeminer42 Python Images for CI builds
+
+Docker Python images used by our CI.
+
+## Dependencies
+
+The following dependencies are being installed on all images:
+
+* ...
+* ...
+
+## Tags
+
+We currently have images for the following versions:
+
+- `?`, `latest` [Dockerfile]()
+
+## Contributing
+
+`Dockerfiles` are stored under folders for each version.
+
+For updating the images, just open a _pull request_ with
+the new `Dockerfile` version and, after accepted, Docker
+Hub will build automatically after a few minutes.
+
+The images should setup an environment that is widely used,
+please don't install dependencies that are specific to a
+project. It's also good to have a pattern and all images
+support the same things, why a ruby version would use
+PhantomJS and the other doesn't?