Support Python 3.7 (#273)

* Ignore temporary files

* Support Python 3.7

This fixes #271.

* Re-enable nightly in Travis CI

This relates to #90.

* Undo 821a069

Author: myint

.travis.yml

@@ -11,9 +11,6 @@ python:
   - pypy-5.3
   - pypy3
   - pypy3.3-5.2-alpha1
-matrix:
-  allow_failures:
-    - python: nightly
 install:
   - pip install flake8==2.1.0 pep8==1.5.6
   - python setup.py install

pyflakes/checker.py

@@ -870,7 +870,19 @@ def handleNode(self, node, parent):
 
     def handleDoctests(self, node):
         try:
-            (docstring, node_lineno) = self.getDocstring(node.body[0])
+            if hasattr(node, 'docstring'):
+                docstring = node.docstring
+
+                # This is just a reasonable guess. In Python 3.7, docstrings no
+                # longer have line numbers associated with them. This will be
+                # incorrect if there are empty lines between the beginning
+                # of the function and the docstring.
+                node_lineno = node.lineno
+                if hasattr(node, 'args'):
+                    node_lineno = max([node_lineno] +
+                                      [arg.lineno for arg in node.args.args])
+            else:
+                (docstring, node_lineno) = self.getDocstring(node.body[0])
             examples = docstring and self._getDoctestExamples(docstring)
         except (ValueError, IndexError):
             # e.g. line 6 of the docstring for <string> has inconsistent