Merge tag '0.0.3' into develop

v0.0.3
add basic entities
post views improvement with bootstrap
comment views improvement with bootstrap
Merge branch 'feature/bootstrap_theme' into develop
use simple_form for forms
add picture in post
add basic user registration entities
add user registration with auth
Merge branch 'feature/user_registration' into develop
add sending e-mail notifications when register or sign in
bump version to 0.0.4
Merge branch 'release/0.0.4'