Fix pyproject.toml license spec

Author: hugetim

pyproject.toml

@@ -24,7 +24,7 @@ classifiers = [
     "Framework :: Jupyter :: JupyterLab :: 3",
     "Framework :: Jupyter :: JupyterLab :: Extensions",
     "Framework :: Jupyter :: JupyterLab :: Extensions :: Prebuilt",
-    "License :: OSI Approved :: MIT",
+    "License :: OSI Approved :: MIT License",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.7",