[doclint] move doclint testing to golden

This patch:
- move doclint testing to golden
- refactor doclint/lint.js to drop specs and everything

utils/doclint/test/02-method-errors/doc.md

@@ -0,0 +1,6 @@
+### class: Foo
+
+#### foo.proceed()
+
+#### foo.start()
+

utils/doclint/test/02-method-errors/foo.js

@@ -0,0 +1,7 @@
+class Foo {
+  start() {
+  }
+
+  stop() {
+  }
+}