Add pyomo to setup.cfg

Author: khaeru

setup.cfg

@@ -31,12 +31,15 @@ docs =
     sphinx >= 3.0
     sphinx_rtd_theme
     sphinxcontrib-bibtex
+pyomo =
+    pyomo
 report =
     genno[compat]
 tutorial =
     jupyter
 tests =
     %(docs)s
+    %(pyomo)s
     %(tutorial)s
     codecov
     memory_profiler
@@ -96,6 +99,8 @@ ignore_missing_imports = True
 ignore_missing_imports = True
 [mypy-pretenders.*]
 ignore_missing_imports = True
+[mypy-pyomo.*]
+ignore_missing_imports = True
 [mypy-requests_cache.*]
 ignore_missing_imports = True
 [mypy-requests_mock.*]