Implemented Collection.delete
Refactored Collection.delete
Collection.replace sets the updated_at timestamp
Collection.replace replaces the document via the connection
Collection.replace sets the rev of the model
Collection.replace should return the model
Collection.replace should validate the model first
CollectionSpec: Explicitly set valid? to true in valid context
Collection.save should return false if the model is invalid
CollectionSpec: Ensure created_at is not updated on replace
Timestamps: Using Time instead of DateTime
Implemented Model#==
CollectionSpec: Changed naming to make it more clear
Collection: Query collection name and model class
Collection: Defaults for mapper, database, connection
DocumentModelMapper added
Satisfied reek
BasicSpec: First spec for Collection works now
Don't install debugger on travis
BasicSpec: Added specs for save and update

Note: Changed to truncate the collections before each spec. If we delete
them they will not be re-created correctly.