Add copy_to_clipboard JS

app/assets/javascripts/copy_to_clipboard.js.coffee

+#= require clipboard
+
+$ ->
+  clipboard = new Clipboard '.js-clipboard-trigger',
+    text: (trigger) ->
+      $target = $(trigger.nextElementSibling || trigger.previousElementSibling)
+      $target.data('clipboard-text') || $target.text().trim()
+
+  clipboard.on 'success', (e) ->
+    $(e.trigger).
+      tooltip(trigger: 'manual', placement: 'auto bottom', title: 'Copied!').
+      tooltip('show')
+
+    # Clear the selection and blur the trigger so it loses its border
+    e.clearSelection()
+    $(e.trigger).blur()
+
+    # Manually hide the tooltip after 1 second
+    setTimeout(->
+      $(e.trigger).tooltip('hide')
+    , 1000)