adding a build environment dockerfile for jbrowse

[scottcain]

Submitting a pull request

Please base your pull request based on the "dev" branch of JBrowse

The default branch is "master" but this contains the last stable release, and new pull requests should be based off of "dev"

Then set the base branch to "dev" on GitHub also

[scottcain]

The image created from this dockerfile is intended to be a parent image for a JBrowse docker file, so that the author of a jbrowse docker file doesn't have to futz with doing this themselves. An example implementation of a JBrowse dockerfile will be forthcoming when this is available on docker hub.

(edited to change "base image" to "parent image"--I had the terminology wrong)

[scottcain]

I nice side effect of having this docker file around is that it also serves as concise documentation of what is needed in a Debian-based environment for building JBrowse.

[cmdcolin]

What happens after this PR is merged? It needs to be published still?

[scottcain]

My understanding is also somewhat rudimentary, but what I think happens is that I have to build an image and then do a push of the image to docker hub. The reality is that this pull request doesn't really do much, other than provide documentation "describing" what we're putting on docker hub.