Several key DFS methods MISSING in 7.0.19

[brinklec]

Several key DFS-related methods, including Graph.reachable, are completely missing from the current release 7.0.19 for 2.12.

Quiver looks like a very nice library and I would like to use it, but the first thing I wanted to use was the Graph.reachable method I saw in the 7.1-SNAPSHOT source on Github. I eventually downloaded the source JAR and confirmed that reachable and several other DFS-based methods are commented out in released 7.0.19 source for 2.12.

Tried also to get sbt to use 7.1-SNAPSHOT, but io.verizon.quiver#core_2.12;7.1-SNAPSHOT: not found.

[rossabaker]

We brought some functions back on master in #31, but it looks like we haven't released again.

We no longer have the publishing infrastructure from Verizon. Other projects, like Nelson and Knobs, have moved to the getnelson organization. I think the best way to revive this would be to move it over there and do a release.