Prepare 0.9.0b1 release

Author: kbattocchi

README.md

@@ -45,10 +45,12 @@ For information on use cases and background material on causal inference and het
 
 # News
 
-**November 20, 2020:** Release v0.8.1, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.8.1)
+**January 20, 2021:** Release v0.9.0b1, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.9.0b1)
 
 <details><summary>Previous releases</summary>
 
+**November 20, 2020:** Release v0.8.1, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.8.1)
+
 **November 18, 2020:** Release v0.8.0, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.8.0)
 
 **September 4, 2020:** Release v0.8.0b1, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.8.0b1)

setup.cfg

@@ -7,11 +7,11 @@ max-line-length=119
 convention=numpy
 
 [build_sphinx]
-version = 0.8.1
+version = 0.9.0b1
 
 [metadata]
 name = econml
-version = 0.8.1
+version = 0.9.0b1
 author = Microsoft Corporation
 description = This package contains several methods for calculating Conditional Average Treatment Effects
 long_description = file: README.md
@@ -28,7 +28,9 @@ classifiers =
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     License :: OSI Approved :: MIT License
-    Operating System :: OS Independent
+    Operating System :: MacOS
+    Operating System :: Microsoft :: Windows
+    Operating System :: POSIX :: Linux
 
 [options]
 packages = find_namespace: