reset floatx and epsilon

Author: kevinykuo

tests/testthat/test-backend.R

@@ -120,11 +120,15 @@ test_backend("k_set_floatx", {
   skip_if_theano()
   k_set_floatx("float16")
   expect_identical(k_floatx(), "float16")
+  k_set_floatx("float32")
+  expect_identical(k_floatx(), "float32")
 })
 
 test_backend("k_set_epsilon", {
   skip_if_cntk()
   skip_if_theano()
   k_set_epsilon(1e-4)
   expect_equal(k_epsilon(), 1e-4)
+  k_set_epsilon(1e-07)
+  expect_equal(k_epsilon(), 1e-07)
 })