Implement dimselect, seeded graph matching

[j1c]

write code, tests, and documentation for the following:

• dimensionality selection
• joint graph embedding base on shangsi paper

DoD:

• finished code with documentation, tests for each
• travis integration for each function added

[jovo]

SGM is pretty complex, there are many variants of it.
if @bstadt is plannign on doing many-to-one, he should probably also engage in this.

[jovo]

what about pass-to-ranks? is that one of the transformatinos?

[bvarjavand]

Slightly modified to do SGM instead of JEG

write code, tests, and documentation for the following:

• dimensionality selection
• seeded graph matching
  DoD:
• finished code with documentation, tests for each
• travis integration for each function added

[j1c]

Closing. At this point, @bvarjavand isn't working on SGM and probably won't anytime soon.