update setup.py

Author: haifeng-jin

setup.py

@@ -8,15 +8,15 @@
 
 setup(
     name='autokeras',
-    version='1.0.0a0',
+    version='1.0.0b0',
     description='AutoML for deep learning',
     package_data={'': ['README.md']},
     long_description=readme.read_text(encoding='utf-8'),
     long_description_content_type='text/markdown',
     author='Data Analytics at Texas A&M (DATA) Lab, Keras Team',
     author_email='[email protected]',
     url='http://autokeras.com',
-    download_url='https://github.com/keras-team/autokeras/archive/1.0.0a0.tar.gz',
+    download_url='https://github.com/keras-team/autokeras/archive/1.0.0b0.tar.gz',
     keywords=['AutoML', 'keras'],
     install_requires=[
         'tensorflow>=2.0.0',