Add unstubbed request fall through.

Currently, Nocilla raises an exception upon an unstubbed request and 
provides a helpful code snippet to stub that request. Now, it will
allow the unstubbed request to fall through, get a response, then 
raise an exception and provide an additional code snippet with the
response.
Remove message assertion for unstubbed request.

We want the exception that is raised upon an unstubbed request to 
provide a code snippet that includes the response, but we can't be 
certain what the response will be, so therefore we can't make an 
assertion on the expected message.
Add new init method and toNocillaDSL method
Move unstubbed response data into a LSStubResponse

Put the unstubbed request's response in an LSStubResponse, then return
a code snippet that will stub out the unstubbed request including
a response.
Merge pull request #1 from smartlogic/add-with-response-snippet

Add with response snippet