Setting the line count of roodi to an obscene number

This test is absolutely useless.
Database#[] is now an alias for Database#collection
Own, private methods for interpretation of server feedback
Removing the timings

I need to scroll in the output of guard everytime,
and I don't need these numbers now.
If I want to work on performance, I can still
run the tests with the options manually.
Collections now have a type #4
Refactoring: Collection's content methods

Preparation for multiple content types
I had to make a tiny change to the spec, because
instead of nothing, the mock gets an empty Hash.
I still think that I had my refactoring hat on.
Preparing Document for parenthood :family: #4

Listen. This is where children come from.
or: A tiny refactoring
Create Collections of multiple content types #4

You can now create collections with content type
:document or :edge. Default is :document
Introducing: Edges #4
An Edge Collection now uses Edges instead of Documents #4
The ID for the From and To Document are now accessible #4
Collections that create Documents and Edges. Closes #4

Edge Collections can only create edges, Document Collections only
documents.
API Change: Collection#create => Collection#create_document