Convert Contribution Column Chart to ECharts

Description

We currently use chartjs to render the contribution column charts found in https://gitlab.com/gitlab-org/gitlab-ce/-/graphs/master/charts. We need to change it to ECharts to

  • Reduce dependency on multiple charting libraries
  • Confirm charts to design pattern

Screenshot

Screen_Shot_2019-07-01_at_5.01.01_PM