Add rack profiler to development

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix migrations and add mysql limits

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'rack-profiler' into 'master'

Rack profiler

See merge request !79
Merge branch 'fix-migrations' into 'master'

Fix migrations

See merge request !80