Drop support for Python 3.4 (#218)

* Removal of enum34 and Python 3.4 classifiers.

PyYAML no longer supports Python 3.4 which is forcing Maestro to
also drop support as it has a direct dependency.

* Addition of python requirements, download url, and maintainer.

* Re-add py2.7. Note: py2.7 unofficially supported.

* Re-add enum34 for py2.7.

* Removal of py34 from tox tests.

* Removal of py3.4 from travis.

.travis.yml

@@ -2,7 +2,6 @@ language: python
 
 python:
     - "2.7"
-    - "3.4"
     - "3.5"
     - "3.6"
 

setup.py

@@ -1,43 +1,46 @@
 from maestrowf import __version__
 from setuptools import setup, find_packages
 
-setup(name='maestrowf',
-      description='A tool and library for specifying and conducting general '
-      'workflows.',
-      version=__version__,
-      author='Francesco Di Natale',
-      author_email='dinatale3@llnl.gov',
-      url='https://github.com/llnl/maestrowf',
-      license='MIT License',
-      packages=find_packages(),
-      entry_points={
-        'console_scripts': [
-            'maestro = maestrowf.maestro:main',
-            'conductor = maestrowf.conductor:main',
-        ]
-      },
-      install_requires=[
-        'PyYAML>=4.2b1',
-        'six',
-        "filelock",
-        "tabulate",
-        "enum34 ; python_version<'3.4'"
-        ],
-      extras_require={},
-      long_description_content_type="text/markdown",
-      classifiers=[
-        'Development Status :: 5 - Production/Stable',
-        'Operating System :: Unix',
-        'Operating System :: MacOS :: MacOS X',
-        'Intended Audience :: Developers',
-        'Intended Audience :: Education',
-        'Intended Audience :: Science/Research',
-        'Topic :: Scientific/Engineering',
-        'Topic :: System :: Distributed Computing',
-        'Programming Language :: Python',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
-        'Programming Language :: Python :: 3.6',
-        'Programming Language :: Python :: 3.7',
-        ],
-      )
+setup(
+  name='maestrowf',
+  description='A tool and library for specifying and conducting general '
+  'workflows.',
+  version=__version__,
+  author='Francesco Di Natale',
+  maintainer='Francesco Di Natale',
+  author_email='dinatale3@llnl.gov',
+  url='https://github.com/llnl/maestrowf',
+  license='MIT License',
+  packages=find_packages(),
+  entry_points={
+    'console_scripts': [
+        'maestro = maestrowf.maestro:main',
+        'conductor = maestrowf.conductor:main',
+    ]
+  },
+  install_requires=[
+    'PyYAML>=4.2b1',
+    'six',
+    "filelock",
+    "tabulate",
+    "enum34 ; python_version<'3.4'"
+  ],
+  extras_require={},
+  long_description_content_type='text/markdown',
+  download_url='https://pypi.org/project/maestrowf/',
+  python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*',
+  classifiers=[
+    'Development Status :: 5 - Production/Stable',
+    'Operating System :: Unix',
+    'Operating System :: MacOS :: MacOS X',
+    'Intended Audience :: Developers',
+    'Intended Audience :: Education',
+    'Intended Audience :: Science/Research',
+    'Topic :: Scientific/Engineering',
+    'Topic :: System :: Distributed Computing',
+    'Programming Language :: Python :: 3',
+    'Programming Language :: Python :: 3.5',
+    'Programming Language :: Python :: 3.6',
+    'Programming Language :: Python :: 3.7',
+  ],
+)

tox.ini

@@ -10,7 +10,6 @@ skip_missing_interpreters=True
 [travis]
 python =
 	2.7: py27
-	3.4: py34
 	3.5: py35
 	3.6: py36