Downgrading rdflib to ~=5.0" as RDFNamespace class is not available in rdflib~=6.0.

setup.py

@@ -14,15 +14,13 @@ setuptools.setup(
     url="https://git.rwth-aachen.de/i5/teaching/jupyter-rdfify",
     packages=setuptools.find_packages(),
     install_requires=[
-        "rdflib~=5.0"#_RDFNamespace class is not available in rdflib~=6.0. So, we need to downgrade it,
+        "rdflib~=5.0",
         "ipython>=7.0.0",
         "graphviz",
         "sparqlwrapper>=1.8.5",
         "sparqlslurper~=0.4",
         "PyShEx",
-        "owlrl"#,
-        #"sparqlslurper @ git+https://git.rwth-aachen.de/rezaul.karim/sparqlslurper.git@master",
-        #"PyShEx @ git+https://git.rwth-aachen.de/rezaul.karim/PyShEx.git@master"
+        "owlrl"
     ],
     classifiers=[
         "Programming Language :: Python :: 3",