Add Dockerfile to build Snap / Adam / Avocado / Spark(?) from source

[davidonlaptop]

Since Adam is in active development, it may be interesting to be able to ship a yet unreleased version of Adam to a user (or developer) for feedback / development.

As mentionned in issue #1, the Dockerfile for building adam from source is quite different than the Dockerfile for building a released version of adam. It is suggested to use a different "adam-src" branch in git which would build the docker image tagged "adam:src".

See also Spark which is released for multiple platforms (spark for hadoop, MapR, CDH4...). There should be 1 image for each match, e.g.:

• Spark 1.2.1 from source
• Spark 1.2.1 prebuilt for Hadoop 2.4
• Spark 1.2.1 prebuilt for Hadoop 2.3
• Spark 1.2.1 prebuilt for Hadoop 1.x
• Spark 1.2.2 ....

The scope is limited to Snap / Adam / Avocado for now, but it may be wise to consider these possibilities in our solution.