Pipe constraints into solver to get solution

[awgreene]

User Story:

• As a Deppy user, I would like to use the solver to decide if a set of constraints can be satisfied by available entities.

Assumptions:

• We assume that entity contains syntactic valid entities

Acceptance Criteria:

• The Deppy library includes the mean for passing a set of constraints into the solver.
• Errors produced are human readable.
• E2E tests should consider:
  -- Invalid entities returned by the registry
  -- Errors when unmarshalling a response
  -- Missing propeties
  -- Invalid Constraints
  -- Unjustifiable constraints
  -- io errors

[perdasilva]

operator-framework/operator-controller#105 closes most of the items here
just need e2e

[awgreene]

I believe this PR introduces the requested e2e test @perdasilva