Start testing PyPy (#357)

* Start testing PyPy

* Update changelog

.travis.yml

@@ -9,9 +9,8 @@ python:
   - "3.6"
   - "3.7"
   - "3.8-dev"
-# TODO (dargueta): Enable these once we figure out FTP timing issues in PyPy tests
-#  - 'pypy'
-#  - 'pypy3.5-7.0'
+  - 'pypy'
+  - 'pypy3.5-7.0'  # Need 7.0+ due to a bug in earlier versions that broke our tests.
 
 matrix:
   include:
@@ -22,6 +21,11 @@ matrix:
       python: '3.7'
       env: TOXENV=lint
 
+  # Temporary bandaid for https://github.com/PyFilesystem/pyfilesystem2/issues/342
+  allow_failures:
+    - python: pypy
+    - python: pypy3.5-7.0
+
 before_install:
   - pip install -U tox tox-travis
   - pip --version

CHANGELOG.md

@@ -5,6 +5,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [2.4.12] - (Unreleased)
+
+### Changed
+
+- Start testing on PyPy. Due to [#342](https://github.com/PyFilesystem/pyfilesystem2/issues/342)
+  we have to treat PyPy builds specially and allow them to fail, but at least we'll
+  be able to see if we break something aside from known issues with FTP tests.
+
 ## [2.4.11] - 2019-09-07
 
 ### Added