Merge branch '470-tox': upgrade setuptools to fix travis

This should also (hopefully) fix the LGTM baseline build, because they appear
to downgrade all dependencies to the lowest declared-acceptable version
before performing their static analysis, and the previous setuptools-11.3 was
too old to support some of the syntax used in zfec's setup.py (specifically
the python clause in `"argparse > 0.8 ; python <= '2.7'"`).

PR 470 updated the declared setuptools requirement, but it broke Travis on
OS-X because that platform had a really old setuptools-18.5, and apparently
upgrading from 18.5 to the current 39.0.1 during the tox process caused
internal consistency problems (probably mixing pieces of the two different
setuptools modules). This branch fixes it by telling travis to upgrade
setuptools before we run tox.

closes tahoe-lafs/tahoe-lafs#470

.travis.yml

@@ -19,7 +19,7 @@ install:
   - if [ "${TRAVIS_OS_NAME}" = "osx" ]; then export PATH=$HOME/Library/Python/2.7/bin:$PATH; fi
   - if [ "${TRAVIS_OS_NAME}" = "osx" ]; then wget https://bootstrap.pypa.io/get-pip.py && sudo python ./get-pip.py; fi
   - pip list
-  - pip install --user codecov tox
+  - pip install --user --upgrade codecov tox setuptools
   - echo $PATH; which python; which pip; which tox
   - python misc/build_helpers/show-tool-versions.py
 script:

src/allmydata/_auto_deps.py

@@ -20,7 +20,7 @@ install_requires = [
     # need pkg_resources . We use >=11.3 here because that's what
     # "cryptography" requires (which is a sub-dependency of TLS-using
     # packages), so there's no point in requiring less.
-    "setuptools >= 11.3",
+    "setuptools >= 28.8.0",
 
     "zfec >= 1.1.0",
 
@@ -150,7 +150,9 @@ import sys
 if not hasattr(sys, 'frozen'):
     package_imports.append(('setuptools', 'setuptools'))
 
-setup_requires = []
+setup_requires = [
+    'setuptools >= 28.8.0',  # for PEP-440 style versions
+]
 
 
 # These are suppressed globally: