spec: test classes with the same name stomp each other

TestCourseApi is also defined in another API spec, with a different set
of methods and mixins. So if you run both spec suites in the same
process, you get errors.

Change-Id: Iff4e0b4926882453821718072586b7ed02ed310a
Reviewed-on: https://gerrit.instructure.com/29266
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Stanley Stuart <stanley@instructure.com>
Product-Review: Brian Palmer <brianp@instructure.com>
QA-Review: Brian Palmer <brianp@instructure.com>

spec/apis/v1/courses_api_spec.rb

@@ -26,7 +26,6 @@ class TestCourseApi
   def api_user_content(syllabus, course); return "api_user_content(#{syllabus}, #{course.id})"; end
 end
 
-
 describe Api::V1::Course do
 
   describe '#course_json' do

spec/apis/v1/discussion_topics_api_spec.rb

@@ -19,7 +19,7 @@
 require File.expand_path(File.dirname(__FILE__) + '/../api_spec_helper')
 require File.expand_path(File.dirname(__FILE__) + '/../locked_spec')
 
-class TestCourseApi
+class DiscussionTopicsTestCourseApi
   include Api
   include Api::V1::DiscussionTopics
   def feeds_topic_format_path(topic_id, code, format); "feeds_topic_format_path(#{topic_id.inspect}, #{code.inspect}, #{format.inspect})"; end
@@ -29,7 +29,7 @@ end
 
 describe Api::V1::DiscussionTopics do
   before do
-    @test_api = TestCourseApi.new
+    @test_api = DiscussionTopicsTestCourseApi.new
     course_with_teacher(:active_all => true, :user => user_with_pseudonym)
     @me = @user
     student_in_course(:active_all => true, :course => @course)