diff --git a/.travis.yml b/.travis.yml
index 89b17c0c..b1ab41ff 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,7 +4,6 @@ python:
 - 2.7
 - 3.4
 - 3.5
-- pypy
 before_install:
 - |
   if [ "$TRAVIS_PYTHON_VERSION" = "pypy" ]; then
diff --git a/graphene/relay/mutation.py b/graphene/relay/mutation.py
index 8db462d6..eb444eed 100644
--- a/graphene/relay/mutation.py
+++ b/graphene/relay/mutation.py
@@ -23,7 +23,8 @@ class ClientIDMutationMeta(ObjectTypeMeta):
         base_name = re.sub('Payload$', '', name)
         if 'client_mutation_id' not in attrs:
             attrs['client_mutation_id'] = String(name='clientMutationId')
-        cls = ObjectTypeMeta.__new__(cls, '{}Payload'.format(base_name), bases, attrs)
+        cls = ObjectTypeMeta.__new__(
+            cls, '{}Payload'.format(base_name), bases, attrs)
         mutate_and_get_payload = getattr(cls, 'mutate_and_get_payload', None)
         if cls.mutate and cls.mutate.__func__ == ClientIDMutation.mutate.__func__:
             assert mutate_and_get_payload, (
@@ -39,8 +40,10 @@ class ClientIDMutationMeta(ObjectTypeMeta):
         else:
             bases += (input_class, )
         input_attrs['client_mutation_id'] = String(name='clientMutationId')
-        cls.Input = type('{}Input'.format(base_name), bases + (InputObjectType,), input_attrs)
-        cls.Field = partial(Field, cls, resolver=cls.mutate, input=Argument(cls.Input, required=True))
+        cls.Input = type('{}Input'.format(base_name), bases +
+                         (InputObjectType,), input_attrs)
+        cls.Field = partial(Field, cls, resolver=cls.mutate,
+                            input=Argument(cls.Input, required=True))
         return cls
 
 
@@ -53,7 +56,7 @@ class ClientIDMutation(six.with_metaclass(ClientIDMutationMeta, ObjectType)):
         def on_resolve(payload):
             try:
                 payload.client_mutation_id = input.get('clientMutationId')
-            except:
+            except Exception:
                 raise Exception((
                     'Cannot set client_mutation_id in the payload object {}'
                 ).format(repr(payload)))
diff --git a/graphene/relay/node.py b/graphene/relay/node.py
index aa6e2dc0..f3c08a5d 100644
--- a/graphene/relay/node.py
+++ b/graphene/relay/node.py
@@ -55,7 +55,8 @@ class NodeMeta(InterfaceMeta):
 
     def __new__(cls, name, bases, attrs):
         cls = InterfaceMeta.__new__(cls, name, bases, attrs)
-        cls._meta.fields['id'] = GlobalID(cls, description='The ID of the object.')
+        cls._meta.fields['id'] = GlobalID(
+            cls, description='The ID of the object.')
         return cls
 
 
@@ -68,7 +69,8 @@ class NodeField(Field):
         self.field_type = type
 
         super(NodeField, self).__init__(
-            # If we don's specify a type, the field type will be the node interface
+            # If we don's specify a type, the field type will be the node
+            # interface
             type or node,
             description='The ID of the object',
             id=ID(required=True)
@@ -94,7 +96,7 @@ class Node(six.with_metaclass(NodeMeta, Interface)):
         try:
             _type, _id = cls.from_global_id(global_id)
             graphene_type = info.schema.get_type(_type).graphene_type
-        except:
+        except Exception:
             return None
 
         if only_type:
diff --git a/graphene/types/datetime.py b/graphene/types/datetime.py
index 0a0e3343..b11671f9 100644
--- a/graphene/types/datetime.py
+++ b/graphene/types/datetime.py
@@ -8,7 +8,7 @@ from .scalars import Scalar
 
 try:
     import iso8601
-except:
+except ImportError:
     raise ImportError(
         "iso8601 package is required for DateTime Scalar.\n"
         "You can install it using: pip install iso8601."