tune max_relative_error in test_cos_sim_op.

python/paddle/v2/framework/tests/test_cos_sim_op.py

@@ -24,15 +24,15 @@ class TestCosSimOp(OpTest):
         self.check_output()
 
     def test_check_grad_normal(self):
-        self.check_grad(['X', 'Y'], 'Out', max_relative_error=0.05)
+        self.check_grad(['X', 'Y'], 'Out', max_relative_error=0.06)
 
     def test_check_grad_ingore_x(self):
         self.check_grad(
-            ['Y'], 'Out', max_relative_error=0.05, no_grad_set=set("X"))
+            ['Y'], 'Out', max_relative_error=0.06, no_grad_set=set("X"))
 
     def test_check_grad_ingore_y(self):
         self.check_grad(
-            ['X'], 'Out', max_relative_error=0.05, no_grad_set=set('Y'))
+            ['X'], 'Out', max_relative_error=0.06, no_grad_set=set('Y'))
 
 
 class TestCosSimOp2(TestCosSimOp):