Enable mypy warnings for unused ignores

Author: cburgdorf

tox.ini

@@ -104,7 +104,7 @@ commands=
     {[common-lint]commands}
     flake8 {toxinidir}/tests --exclude="trinity,p2p"
     # TODO: Drop --ignore-missing-imports once we have type annotations for eth_utils, coincurve and cytoolz
-    mypy --follow-imports=silent --ignore-missing-imports --no-strict-optional --check-untyped-defs --disallow-incomplete-defs -p eth
+    mypy --follow-imports=silent --warn-unused-ignores --ignore-missing-imports --no-strict-optional --check-untyped-defs --disallow-incomplete-defs -p eth
 
 [testenv:py36-lint]
 deps = {[common-lint]deps}
@@ -116,5 +116,5 @@ commands=
     flake8 {toxinidir}/trinity
     flake8 {toxinidir}/scripts
     # TODO: Drop --ignore-missing-imports once we have type annotations for eth_utils, coincurve and cytoolz
-    mypy --follow-imports=silent --ignore-missing-imports --no-strict-optional --check-untyped-defs --disallow-incomplete-defs --disallow-untyped-defs --disallow-any-generics scripts/benchmark
-    mypy --follow-imports=silent --ignore-missing-imports --no-strict-optional --check-untyped-defs --disallow-incomplete-defs --disallow-untyped-defs --disallow-any-generics -p p2p -p trinity
+    mypy --follow-imports=silent --warn-unused-ignores --ignore-missing-imports --no-strict-optional --check-untyped-defs --disallow-incomplete-defs --disallow-untyped-defs --disallow-any-generics scripts/benchmark
+    mypy --follow-imports=silent --warn-unused-ignores --ignore-missing-imports --no-strict-optional --check-untyped-defs --disallow-incomplete-defs --disallow-untyped-defs --disallow-any-generics -p p2p -p trinity