refactor: remove AbstractResume base class

(1) AbstractResume adds complexity without contributing utility. There's not
really a clean "class" abstraction in JavaScript to begin with; CoffeeScript
classes, as nice as they are syntactically, occlude the issue even further.

(2) AbstractResume currently functions as a container for exactly two functions
which arguably should live outside the resume class anyway.

src/utils/resume-scrubber.coffee

@@ -0,0 +1,47 @@
+module.exports =
+
+  ###*
+  Removes ignored or private fields from a resume object
+  @returns an object with the following structure:
+  {
+    scrubbed: the processed resume object
+    ignoreList: an array of ignored nodes that were removed
+    privateList: an array of private nodes that were removed
+  }
+  ###
+  scrubResume: (rep, opts) ->
+    traverse = require 'traverse'
+    ignoreList = []
+    privateList = []
+    includePrivates = opts && opts.private
+
+    scrubbed = traverse( rep ).map () -> # [^1]
+      if !@isLeaf
+        if @node.ignore == true || @node.ignore == 'true'
+          ignoreList.push @node
+          @delete()
+        else if (@node.private == true || @node.private == 'true') && !includePrivates
+          privateList.push @node
+          @delete()
+      if _.isArray(@node) # [^2]
+        @after () ->
+          @update _.compact this.node
+          return
+      return
+
+    scrubbed: scrubbed
+    ingoreList: ignoreList
+    privateList: privateList
+
+
+
+# [^1]: As of v0.6.6, the NPM traverse library has a quirk when attempting
+# to remove array elements directly using traverse's `this.remove`. See:
+#
+# https://github.com/substack/js-traverse/issues/48
+#
+# [^2]: The workaround is to use traverse's 'this.delete' to nullify the value
+# first, followed by removal with something like _.compact.
+#
+# https://github.com/substack/js-traverse/issues/48#issuecomment-142607200
+#