Chartkick Error - SQLite

I'm trying to include chart into my Rails APP, but getting this error:

Gemfile

gem 'chartkick', '~> 1.2.4'
gem 'groupdate', '~> 2.1.1'
gem 'active_median', '~> 0.1.0'

Controller

@commits = Bitbucket.all

View

JS - <%= javascript_include_tag "http://ift.tt/zYvreR", "chartkick" %>
CHART - <%= line_chart @commits.group_by_day(:date, format: "%Y-%m-%d").count %>

Anyone know where is problem?