Made responsive html design.

@mosic 
This shouldn't be necessary, bootstrap is already added to the stylesheet previously: https://github.com/evercam/cambase/blob/0a08d52ca90fd4bd767d203e59b5e3e3e45e9b03/app/assets/stylesheets/application.css.scss#L33

If you need a newer version of bootstrap just update the gem "gem 'bootstrap-sass'".