Add dev deps

backend/dev-requirements.in

@@ -0,0 +1,2 @@
+autopep8
+pip-tools

backend/dev-requirements.txt

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+#
+# This file is autogenerated by pip-compile with python 3.8
+# To update, run:
+#
+#    pip-compile dev-requirements.in
+#
+--trusted-host pypi.org
+
+autopep8==1.6.0
+    # via -r dev-requirements.in
+click==8.0.3
+    # via pip-tools
+pep517==0.12.0
+    # via pip-tools
+pip-tools==6.4.0
+    # via -r dev-requirements.in
+pycodestyle==2.8.0
+    # via autopep8
+toml==0.10.2
+    # via autopep8
+tomli==2.0.0
+    # via pep517
+wheel==0.37.0
+    # via pip-tools
+
+# The following packages are considered to be unsafe in a requirements file:
+# pip
+# setuptools