Use chartkick globally

* Clean up legacy charting imports
* Update existing donut and line charts
* Create helpers for parsing out existing chart data
* Move chart partials to a more common path

config/initializers/chartkick.rb

@@ -0,0 +1,4 @@
+Chartkick.options = {
+  height:      '150px',
+  content_for: :charts_js
+}