Test TimedStack#push
Test TimedStack#pop
Alphabetize tests
Test TimedStack#empty?
Test TimedStack#length
Test TimedStack#shutdown
Test TimedStack#push after shutdown independently

This is a partial refactor of test_shutdown
Test TimedStack#pop with an item
Test TimedStack#pop after shutdown
Test TimedStack#pop when waiting for a push
Do not wait at all for pop
Match style from test_connection_pool.rb
Merge pull request #48 from drbrain/test_connection_pool_timed_stack

Test ConnectionPool::TimedStack