❓ python 2 builds might be failing because of percy parallelization

Getting the error:
```
{"errors":[{"status":"conflict","detail":"Can only finalize pending
builds"}]}
E
======================================================================
ERROR: tearDownClass (tests.test_race_conditions.Tests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/IntegrationTests.py", line 42, in tearDownClass
    cls.percy_runner.finalize_build()
  File
"/home/circleci/repo/venv/lib/python2.7/site-packages/percy/runner.py",
line 98, in finalize_build
    self.client.finalize_build(self._current_build['data']['id'])
  File
"/home/circleci/repo/venv/lib/python2.7/site-packages/percy/client.py",
line 83, in finalize_build
    return self._connection.post(path=path, data={})
  File
"/home/circleci/repo/venv/lib/python2.7/site-packages/percy/connection.p
y", line 64, in post
    raise e
HTTPError: 409 Client Error: Conflict for url:
https://percy.io/api/v1/builds/1665589/finalize
```

Our code might not be work with Percy’s parallelization features
(https://docs.percy.io/docs/parallel-test-suites). So, try combining
into a single `test_render` file

Author: chriddyp

package.json

@@ -15,7 +15,7 @@
     "format": "prettier --config .prettierrc --write src/**/*.js src/**/*.react.js",
     "format:test": "prettier --config .prettierrc src/**/*.js src/**/*.react.js --list-different",
     "test": "npm run lint",
-    "test:py": "python -m unittest -v tests.test_clientside tests.test_render tests.test_race_conditions"
+    "test:py": "python -m unittest -v tests.test_render tests.test_race_conditions"
   },
   "author": "chriddyp",
   "license": "MIT",