setup.py: Don't require flake8 to build, only to run tests

Author: projectgus

.travis.yml

@@ -8,4 +8,5 @@ python:
 
 script:
   - python setup.py build
+  - pip install flake8 flake8-future-import  # matches tests_require in setup.py, a bit hacky
   - python setup.py flake8

setup.py

@@ -78,8 +78,8 @@ def find_version(*file_paths):
         'License :: OSI Approved :: GNU General Public License v2 or later (GPLv2+)',
         'Programming Language :: Python :: 2.7',
     ],
-    setup_requires=[
-        'flake8<3.0.0',
+    tests_require=[
+        'flake8>=3.2.0',
         'flake8-future-import',
     ],
     install_requires=[