Fix typos (#94)

* fix docs

ppgan/utils/options.py

@@ -16,7 +16,7 @@ import argparse
 
 
 def parse_args():
-    parser = argparse.ArgumentParser(description='Segmentron')
+    parser = argparse.ArgumentParser(description='PaddleGAN')
     parser.add_argument('--config-file',
                         metavar="FILE",
                         help='config file path')

ppgan/utils/registry.py

@@ -16,7 +16,7 @@
 class Registry(object):
     """
     The registry that provides name -> object mapping, to support third-party users' custom modules.
-    To create a registry (inside segmentron):
+    To create a registry (inside ppgan):
     .. code-block:: python
         BACKBONE_REGISTRY = Registry('BACKBONE')
     To register an object: