Remove ndex2 version constraint

Author: bgyori

setup.py

@@ -11,7 +11,7 @@
 def main():
     install_list = ['pysb>=1.3.0', 'objectpath',
                     'requests>=2.11', 'lxml', 'ipython', 'future',
-                    'networkx>=3', 'pandas>=2', 'ndex2==2.0.1', 'jinja2',
+                    'networkx>=3', 'pandas>=2', 'ndex2', 'jinja2',
                     'protmapper>=0.0.29', 'obonet',
                     'tqdm', 'pybiopax>=0.0.5']