Issue Origin: https://github.com/keras-team/keras-tuner/issues/198
Issue Origin:
https://github.com/keras-team/keras-tuner/issues/198

The hardcoded forward slash value for _SHARDED_SUFFIX broke on windows since the windows file system does not except forward slashes.

tensorflow/tensorflow-pywrap_tf_optimizer,petewarden/tensorflow,annarev/tensorflow,sarvex/tensorflow,annarev/tensorflow,sarvex/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow,Intel-Corporation/tensorflow,gautam1858/tensorflow,Intel-tensorflow/tensorflow,annarev/tensorflow,frreiss/tensorflow-fred,paolodedios/tensorflow,Intel-tensorflow/tensorflow,yongtang/tensorflow,yongtang/tensorflow,annarev/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,Intel-tensorflow/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow,petewarden/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,yongtang/tensorflow,tensorflow/tensorflow,gautam1858/tensorflow,Intel-tensorflow/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,frreiss/tensorflow-fred,gautam1858/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_saved_model,paolodedios/tensorflow,yongtang/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow,annarev/tensorflow,annarev/tensorflow,karllessard/tensorflow,karllessard/tensorflow,gautam1858/tensorflow,paolodedios/tensorflow,karllessard/tensorflow,annarev/tensorflow,frreiss/tensorflow-fred,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_saved_model,frreiss/tensorflow-fred,sarvex/tensorflow,sarvex/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,yongtang/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,annarev/tensorflow,frreiss/tensorflow-fred,petewarden/tensorflow,frreiss/tensorflow-fred,annarev/tensorflow,petewarden/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,yongtang/tensorflow,sarvex/tensorflow,petewarden/tensorflow,yongtang/tensorflow,Intel-tensorflow/tensorflow,karllessard/tensorflow,frreiss/tensorflow-fred,Intel-Corporation/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,frreiss/tensorflow-fred,Intel-Corporation/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,gautam1858/tensorflow,petewarden/tensorflow,Intel-tensorflow/tensorflow,karllessard/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,frreiss/tensorflow-fred,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-pywrap_tf_optimizer,frreiss/tensorflow-fred,annarev/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,sarvex/tensorflow,Intel-Corporation/tensorflow,petewarden/tensorflow,karllessard/tensorflow,karllessard/tensorflow,yongtang/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,petewarden/tensorflow,petewarden/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_saved_model,frreiss/tensorflow-fred,paolodedios/tensorflow,tensorflow/tensorflow,petewarden/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_saved_model,paolodedios/tensorflow,tensorflow/tensorflow,sarvex/tensorflow,yongtang/tensorflow,paolodedios/tensorflow,yongtang/tensorflow,Intel-tensorflow/tensorflow,gautam1858/tensorflow,petewarden/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_saved_model,frreiss/tensorflow-fred,sarvex/tensorflow,tensorflow/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,Intel-Corporation/tensorflow,gautam1858/tensorflow,gautam1858/tensorflow,annarev/tensorflow,tensorflow/tensorflow,gautam1858/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,paolodedios/tensorflow,Intel-tensorflow/tensorflow,Intel-Corporation/tensorflow,petewarden/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-experimental_link_static_libraries_once,yongtang/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once