Set random seed for TensorFlow to make test repro (#685)

Author: Squadrick

tensorflow_addons/optimizers/lookahead_test.py

@@ -29,6 +29,7 @@
 class LookaheadTest(tf.test.TestCase):
     def run_dense_sample(self, iterations, optimizer, seed=0x2019):
         np.random.seed(seed)
+        tf.random.set_seed(seed)
 
         val_0 = np.random.random((2,))
         val_1 = np.random.random((2,))
@@ -56,6 +57,7 @@ def run_dense_sample(self, iterations, optimizer, seed=0x2019):
 
     def run_sparse_sample(self, iterations, optimizer, seed=0x2019):
         np.random.seed(seed)
+        tf.random.set_seed(seed)
 
         val_0 = np.random.random((2,))
         val_1 = np.random.random((2,))
@@ -109,6 +111,7 @@ def test_sparse_exact_ratio(self):
 
     def test_fit_simple_linear_model(self):
         np.random.seed(0x2019)
+        tf.random.set_seed(0x2019)
 
         x = np.random.standard_normal((100000, 3))
         w = np.random.standard_normal((3, 1))