Remove --no-preserve=all build_pip_package.py
Remove --no-preserve=all build_pip_package.py

This commit removes --no-preserve=all from
syntaxnet/dragnn/tools/build_pip_package.py. It was causing issues for
OSX developers, as that option is not available on OSX.

tombstone/models,sshleifer/object_detection_kitti,r888888888/models,alexgorban/models,jazcollins/models,xcyan/models,zbigniewwojna/text-rcnn,jazcollins/models,sshleifer/object_detection_kitti,xcyan/models,r888888888/models,cshallue/models,derekjchow/models,jch1/models,jazcollins/models,derekjchow/models,jazcollins/models,jch1/models,sshleifer/object_detection_kitti,tombstone/models,jiaphuan/models,jiaphuan/models,jch1/models,tombstone/models,jiaphuan/models,cshallue/models,r888888888/models,jiaphuan/models,sshleifer/object_detection_kitti,jiaphuan/models,jiaphuan/models,xcyan/models,derekjchow/models,xcyan/models,jch1/models,r888888888/models,derekjchow/models,alexgorban/models,tombstone/models,sshleifer/object_detection_kitti,tombstone/models,xcyan/models,jch1/models,sshleifer/object_detection_kitti,cshallue/models,cshallue/models,xcyan/models,alexgorban/models,jazcollins/models,alexgorban/models,jch1/models,jazcollins/models,tombstone/models,r888888888/models,cshallue/models,alexgorban/models,derekjchow/models,r888888888/models