Change required python version to 3.4 or above, remove version 3.7

Signed-off-by: Dan Yeaw <[email protected]>

setup.py

@@ -25,7 +25,7 @@
     author_email='[email protected]',
     url='http://pybee.org/rubicon',
     packages=find_packages(exclude=['tests']),
-    python_requires='>=3.5',
+    python_requires='>=3.4',
     namespace_packages=['rubicon'],
     license='New BSD',
     classifiers=[
@@ -34,9 +34,9 @@
         'License :: OSI Approved :: BSD License',
         'Programming Language :: Objective C',
         'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
-        'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3 :: Only',
         'Topic :: Software Development',
     ],

tox.ini

@@ -4,13 +4,13 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = {py35,py36,py37,pypy3}-{default,i386},flake8
+envlist = {py34,py35,py36,pypy3}-{default,i386},flake8
 
 [testenv]
 basepython = 
+    py34: python3.4
     py35: python3.5
     py36: python3.6
-    py37: python3.7
     pypy3: pypy3
 
 whitelist_externals =