Add TimeTravel.return method and preserve float precision

Author: bolshakov

spec/support/time_travel.rb

@@ -8,7 +8,7 @@ class << self
       def freeze(time = Time.now)
         if block_given?
           Timecop.freeze(time) do
-            redis_time_ms = (Time.now.to_f * 1000).to_i
+            redis_time_ms = Time.now.to_f * 1000.0
             redis.rpush(STACK_KEY, redis_time_ms)
             begin
               yield
@@ -19,11 +19,16 @@ def freeze(time = Time.now)
         else
           redis.del(STACK_KEY)
           Timecop.freeze(time)
-          redis_time_ms = (Time.now.to_f * 1000).to_i
+          redis_time_ms = Time.now.to_f * 1000.0
           redis.rpush(STACK_KEY, redis_time_ms)
         end
       end
 
+      def return
+        redis.del(STACK_KEY)
+        Timecop.return
+      end
+
       private
 
       def redis