FIX: Reset state of `DiscourseRedis::FallbackHandler` in tests.

lib/discourse_redis.rb

@@ -64,6 +64,13 @@ class DiscourseRedis
       end
     end
 
+    # Used for testing
+    def reset!
+      @master = true
+      @last_checked = nil
+      @running = false
+    end
+
     private
 
     def synchronize

spec/components/discourse_redis_spec.rb

@@ -78,6 +78,10 @@ describe DiscourseRedis do
   end
 
   describe DiscourseRedis::FallbackHandler do
+    after do
+      fallback_handler.reset!
+    end
+
     describe '#initiate_fallback_to_master' do
       it 'should fallback to the master server once it is up' do
         begin