Don't generate an owner_id in Current factory

Don't generate an 'owner_id' as the value should be set in the Currents
controller when the Current is created.
Set valid and invalid attributes for Currents

Use attribute hashes to pass factory-generated values to the Currents
controller for testing. Invalid attributes only assigns the Current's
title to be 'nil.'
Sign in and use a valid user in Currents spec

Before each Currents spec, create and sign in a test user. The users'
session key is passed in the 'valid_session' hash for each request made
in the spec.
Pass generated user in as owner of Current

Pass the user generated in the 'before(:each)' block of the Currents
spec in as the owner of the test Current record being created.
Fix request and expectation of 'GET show'

'GET show' returns only a single '@current' in the Currents controller.
'@currents,' is always nil. Expect a single current instead of an array
of currents.
Create test records with (in)valid attributes

Create records to test specs against with the hashes of values
generated by the Currents factory.
Fix Currents spec expectation syntax

Expectations should be in the format 'expect(...).to' instead of
'...should.'
Fix 'PUT' update parameters

Pass valid values to update the currents record with in the Current's
controller 'PUT update' spec.
Fix Currents controller spec bracket spacing
Authenticate users in Currents controller

Before users are allowed to add, change, or delete Currents records,
their accounts need to be authenticated.
Set Currents owner in 'create' action
Use strong parameters to filter hashes

Use Rails' 'strong_parameters' to filter the values passed to the
controller for creating and updating Currents records.