update test server_config and mitigate https://github.com/librosa/librosa/issues/1160 in server package test

tests/inputs/server_config.json

@@ -6,7 +6,7 @@
     "wavernn_file": null, // wavernn checkpoint file name
     "wavernn_config": null, // wavernn config file
     "vocoder_config":null,
-    "vocoder_file": null,
+    "vocoder_checkpoint": null,
     "is_wavernn_batched":true,
     "port": 5002,
     "use_cuda": false,

tests/test_server_package.sh

@@ -14,6 +14,9 @@ rm -f dist/*.whl
 python setup.py --quiet bdist_wheel --checkpoint tests/outputs/checkpoint_10.pth.tar --model_config tests/outputs/dummy_model_config.json
 pip install --quiet dist/TTS*.whl
 
+# this is related to https://github.com/librosa/librosa/issues/1160
+pip install numba==0.48
+
 python -m TTS.server.server &
 SERVER_PID=$!