add model micropost
I forgot
add connection between user and micropost
add factory to generate micropost
add test cases

whether microposts are in the right order
set default order
connection between user and micropost accomplished
annotated Micropost
validate content
add test cases

profile page
add microposts page
show microposts
routes to microposts
add test cases

authorization for non-signed-in users
refactoring

move signed_in_user
add controller micropost
add test cases of micropost page
modified home page when signen in
refactoring err msg snippet
modified snippets after err msg snippet changed