chore: use latest sphinx (#118)

Author: busunkim96

noxfile.py

@@ -183,7 +183,7 @@ def docs(session):
     """Build the docs for this library."""
 
     session.install("-e", ".")
-    session.install("sphinx<3.0.0", "alabaster", "recommonmark")
+    session.install("sphinx", "alabaster", "recommonmark")
 
     shutil.rmtree(os.path.join("docs", "_build"), ignore_errors=True)
     session.run(

synth.py

@@ -53,6 +53,7 @@
 python.py_samples(skip_readmes=True)
 
 # Fix missing async client in datatransfer_v1
+# https://github.com/googleapis/gapic-generator-python/issues/815
 s.replace(
     "google/cloud/bigquery_datatransfer_v1/__init__.py",
     r"from \.services\.data_transfer_service import DataTransferServiceClient",
@@ -64,8 +65,4 @@
     '\\g<0>\n    "DataTransferServiceAsyncClient"',
 )
 
-
-# TODO(busunkim): Use latest sphinx after microgenerator transition
-s.replace("noxfile.py", "'sphinx'", '"sphinx<3.0.0"')
-
 s.shell.run(["nox", "-s", "blacken"], hide_output=False)