Update requirements.txt

Author: vera121

python/requirements.txt

@@ -8,7 +8,7 @@ h5py>=2.2.0
 leveldb==0.20
 networkx==2.2
 nose>=1.3.0
-"pandas<=1.4.4"
+pandas<=1.4.4
 python-dateutil>=2.6.0
 protobuf>=2.5.0
 python-gflags>=2.0