add autopep8

Signed-off-by: Jess Frazelle <github@jessfraz.com>

kittycad/models/valid_source_file_format.py

@@ -1,12 +1,11 @@
 from enum import Enum
 
-
 class ValidSourceFileFormat(str, Enum):
-    STL = 'stl'
-    OBJ = 'obj'
-    DAE = 'dae'
-    STEP = 'step'
-    FBX = 'fbx'
+	STL = 'stl'
+	OBJ = 'obj'
+	DAE = 'dae'
+	STEP = 'step'
+	FBX = 'fbx'
 
-    def __str__(self) -> str:
-        return str(self.value)
+	def __str__(self) -> str:
+		return str(self.value)