setup.py: install_requires in alphabetical order

setup.py

@@ -48,14 +48,14 @@ setup(
     version=versioneer.get_version(),
     install_requires=[
         "docker",
-        "traitlets",
-        "python-json-logger",
         "escapism",
         "jinja2",
+        "python-json-logger",
         "requests",
         "ruamel.yaml>=0.15",
-        "toml",
         "semver",
+        "toml",
+        "traitlets",
     ],
     python_requires=">=3.6",
     author="Project Jupyter Contributors",