Add JLab classifiers and remove python dep (#51)

* Add JLab classifiers and remove python dep

* Bump to 3.5.0

Author: fcollonval

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@jlab-enhanced/cell-toolbar",
-  "version": "3.4.2",
+  "version": "3.5.0",
   "description": "A cell toolbar for JupyterLab.",
   "keywords": [
     "jupyter",

setup.py

@@ -45,24 +45,26 @@
     long_description= long_description,
     long_description_content_type="text/markdown",
     packages=setuptools.find_packages(),
-    install_requires=[
-        "jupyterlab>=3.0.0rc13,==3.*",
-        "packaging"
-    ],
+    install_requires=[],
     zip_safe=False,
     include_package_data=True,
-    python_requires=">=3.6",
+    python_requires=">=3.7",
     license="BSD-3-Clause",
     platforms="Linux, Mac OS X, Windows",
     keywords=["Jupyter", "JupyterLab", "JupyterLab3"],
     classifiers=[
         "License :: OSI Approved :: BSD License",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
         "Framework :: Jupyter",
+        "Framework :: Jupyter :: JupyterLab",
+        "Framework :: Jupyter :: JupyterLab :: 3",
+        "Framework :: Jupyter :: JupyterLab :: Extensions",
+        "Framework :: Jupyter :: JupyterLab :: Extensions :: Prebuilt",
     ],
 )