Solve exercises from chapter 10
Add Micropost model
Basic validation of Micropost
Content validation microposts + show microposts in user show page
Test micropost
Micropost create&destroy action authorization
New micropost form & refactoring
Finish Micropost create action
Deleting microposts
Test micropost creation & deletion
Add image upload with validation on size and dims
Merge branch 'user-microposts' into develop

Finish user-micropost branch
Merge branch 'develop'

Prepare to next release