diff --git a/.travis.yml b/.travis.yml
index 87aea137..8cd9e0c2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,8 +9,6 @@ matrix:
       python: 3.5
     - env: TOXENV=py36
       python: 3.6
-    - env: TOXENV=py37
-      python: 3.7
     - env: TOXENV=pypy
       python: pypy-5.7.1
     - env: TOXENV=pre-commit
diff --git a/graphene/utils/thenables.py b/graphene/utils/thenables.py
index c1fab663..d18d7e61 100644
--- a/graphene/utils/thenables.py
+++ b/graphene/utils/thenables.py
@@ -18,7 +18,7 @@ try:
     from .thenables_asyncio import await_and_execute
 except ImportError:
 
-    def isawaitable(obj):
+    def isawaitable(obj):  # type: ignore
         return False
 
 
diff --git a/graphene/utils/thenables_asyncio.py b/graphene/utils/thenables_asyncio.py
index 3c01b1a2..d5f93182 100644
--- a/graphene/utils/thenables_asyncio.py
+++ b/graphene/utils/thenables_asyncio.py
@@ -3,4 +3,3 @@ def await_and_execute(obj, on_resolve):
         return on_resolve(await obj)
 
     return build_resolve_async()
-
diff --git a/tests_asyncio/test_relay_mutation.py b/tests_asyncio/test_relay_mutation.py
index 2992c8ee..42ea5fc7 100644
--- a/tests_asyncio/test_relay_mutation.py
+++ b/tests_asyncio/test_relay_mutation.py
@@ -1,16 +1,7 @@
 import pytest
 from graphql.execution.executors.asyncio import AsyncioExecutor
 
-from graphene.types import (
-    ID,
-    Argument,
-    Field,
-    InputField,
-    InputObjectType,
-    NonNull,
-    ObjectType,
-    Schema,
-)
+from graphene.types import ID, Field, ObjectType, Schema
 from graphene.types.scalars import String
 from graphene.relay.mutation import ClientIDMutation
 
diff --git a/tox.ini b/tox.ini
index d52ea642..2b7ae59c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,11 +3,11 @@ envlist = flake8,py27,py34,py35,py36,py37,pre-commit,pypy,mypy
 skipsdist = true
 
 [testenv]
-deps = 
+deps =
     .[test]
     py{35,36,37}: pytest-asyncio
 setenv =
-     PYTHONPATH = .:{envdir}    
+     PYTHONPATH = .:{envdir}
 commands =
     py{27,34,py}: py.test --cov=graphene graphene examples {posargs}
     py{35,36,37}: py.test --cov=graphene graphene examples tests_asyncio {posargs}