Move coverage.rc -> setup.cfg to reduce the number of config files (GH-2984)

.coveragerc

-[run]
-branch = True
-parallel = True
-concurrency = multiprocessing,thread
-include = Cython/*
-source = Cython
-omit = Test*

setup.cfg

@@ -13,4 +13,13 @@ ignore =
     S001,
     # S001 found module formatter
     E226,
-    # E226 missing whitespace around operator
+    # E226 missing whitespace around operator[run]
+
+[coverage:run]
+branch = True
+parallel = True
+concurrency = multiprocessing,thread
+include = Cython/*
+source = Cython
+omit = Test*
+