Add bedr package to Docker and dependencies

[jaclyn-taroni]

Purpose/implementation

This is adding the bedr R package and what it wraps up (e.g., bedtools) to the project Docker image.

Issue

#186 (comment)

Docker and continuous integration

Check all those that apply or remove this section if it is not applicable.

• The dependencies required to run the code in this pull request have been added to the project Dockerfile.
• This analysis has been added to continuous integration.

[jashapiro]

🐿