Add pandas-gbq to clientlibs download metrics (#141)

* Add pandas-gbq to clientlibs download metrics

* Create table for third party client libs

Author: liyanhui1228

perf-dashboard/clientlibs-download/python_clientlibs_download.py

@@ -28,7 +28,14 @@
 VENEER_TABLE_NAME = 'veneer_client_libs'
 STACKDRIVER_TABLE_NAME = 'stackdriver_client_libs'
 GRPC_TABLE_NAME = 'grpc_lib'
-TABLES = [VENEER_TABLE_NAME, GRPC_TABLE_NAME, STACKDRIVER_TABLE_NAME]
+THIRD_PARTY_TABLE_NAME = 'third_party_client_libs'
+
+TABLES = [
+    VENEER_TABLE_NAME,
+    GRPC_TABLE_NAME,
+    STACKDRIVER_TABLE_NAME,
+    THIRD_PARTY_TABLE_NAME,
+]
 
 CLIENTLIBS = {
     VENEER_TABLE_NAME: [
@@ -54,6 +61,9 @@
     GRPC_TABLE_NAME: [
         'grpcio',
     ],
+    THIRD_PARTY_TABLE_NAME: [
+        'pandas-gbq',
+    ]
 }