Moved prometheus-flask-exporter into extras_require

setup.cfg

@@ -1,2 +1,30 @@
 [metadata]
-description-file = README.md
+description_file = README.md
+description = "Cellxgene Gateway"
+author = "Niket Patel, Yohann Potier, Alok Saldanha"
+author_email = "alok.saldanha@novartis.com"
+long_description_content_type="text/markdown"
+license = "MIT"
+keywords ="visualization, genomics"
+url = "http://github.com/Novartis/cellxgene-gateway"
+python_requires = ">=3.6"
+classifier =
+    "Topic :: Scientific/Engineering :: Visualization"
+
+[options]
+install_requires =
+    cellxgene
+    flask
+    flask-api
+    werkzeug
+    psutil
+    requests
+    typer
+
+[options.extras_require]
+prometheus =
+    prometheus-flask-exporter
+
+[entry_points]
+console_scripts =
+    cellxgene-gateway = cellxgene_gateway.cli:run