Merge pull request #14123 from shippingwang/fix_import_plot_py3

Fix import plot in py3

test=release/1.1

Author: panyx0718

python/paddle/utils/__init__.py

@@ -12,5 +12,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from plot import Ploter
+from .plot import Ploter
 __all__ = ['dump_config', 'Ploter']