user_spec.rb: added 4 tests from Hartl listing 10.35
user.rb: added 'feed' method
static_pages_spec.rb: added test from Hartl listing 10.37
static_pages_controller.rb: modified 'home' action to have content from Hartl listing 10.38
_feed.h.e: added content from Hartl listing 10.39
_feed_item.h.e: added content from Hartl listing 10.40
_feed.h.e: fixed typo
static_pages/home.h.e: added content from Hartl listing 10.41
static_pages_spec.rb: fixed typo
microposts_controller.rb: set @feed_items to [] if micropost submission fails so tests don't break
_micropost.h.e: added content from Hartl listing 10.43
_micropost.h.e: fixed typo
_feed_item.h.e: added content from Hartl listing 10.44
micropost_pages_spec.rb: added test from Hartl listing 10.45
microposts_controller.rb: modified 'destroy' action, created 'correct_user' method, created :correct_user before_action
user_spec.rb: fixed typo