Bump botorch version in preparation for Ax release (#1170)

Summary:
Pull Request resolved: #1170

Need to release an Ax patch that includes D39654724 (2d7500e) to address pandas update incompatibility

Reviewed By: pcanaran

Differential Revision: D39861608

fbshipit-source-id: bee083281e84f931917f9eef52edd7a83e98ac0b

setup.py

@@ -9,7 +9,7 @@
 from setuptools import find_packages, setup
 
 # TODO: read pinned Botorch version from a shared source
-PINNED_BOTORCH_VERSION = "0.7.1"
+PINNED_BOTORCH_VERSION = "0.7.2"
 
 if os.environ.get("ALLOW_BOTORCH_LATEST"):
     # allows a more recent previously installed version of botorch to remain