Add options hash to Solve.it! method, move ui object into options hash

Add options hash to Solver.resolve

Produce a topologically sorted list of ["Artifact", "Version"] pairs as
the solution if :sorted is true
Trap TSort::Cyclic error when trying to sort, wrap it in a
Solve::Errors::UnsortableSolutionError that also contains the unsorted
solution so that people may be able to recover
remove require 'pry'
Merge branch 'master' into add_sorted_option

Conflicts:
	lib/solve/solver.rb
Merge pull request #24 from RiotGames/add_sorted_option

Add sorted option