spec: fix aux build by pinning old rubocop version

This reverts commit 2073553507.
This reverts commit 56381d06b4.

rubocop upgraded today, and we tried a couple times to fix it, but since
we only run rubocop when ruby files change, the fixes themselves passed
the build but didn't fully fix the problem.  for now, until we can
complete an upgrade, just pin the known working version of rubocop.

Change-Id: Ib7587e5ff9f3c00817f920506208a0e20444d379
Reviewed-on: https://gerrit.instructure.com/70356
Reviewed-by: Jon Jensen <jon@instructure.com>
Tested-by: Jenkins
Product-Review: Jon Jensen <jon@instructure.com>
QA-Review: Jon Jensen <jon@instructure.com>

.rubocop.yml

@@ -68,7 +68,7 @@ Style/IndentHash:
   Enabled: false
 Style/DoubleNegation:
   Enabled: false
-Style/TrailingCommaInLiteral:
+Style/TrailingComma:
   Enabled: false
 Style/MethodCallParentheses:
   Enabled: false

gems/rubocop-canvas/lib/rubocop_canvas/cops/migration/primary_key.rb

@@ -1,5 +1,3 @@
-require 'parser/current'
-
 module RuboCop
   module Cop
     module Migration

gems/rubocop-canvas/rubocop-canvas.gemspec

@@ -14,7 +14,7 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_runtime_dependency "rubocop", "~> 0.36.0"
+  spec.add_runtime_dependency "rubocop", "0.35.1"
   spec.add_development_dependency "bundler", "~> 1.7"
   spec.add_development_dependency "rake", "~> 10.0"
   spec.add_development_dependency "rspec", "~> 3.2.0"