add support for python 2.7

Author: sanfilip

setup.py

@@ -21,12 +21,12 @@
         'Intended Audience :: Developers',
         'Topic :: Software Development :: Libraries',
         'License :: OSI Approved :: ISC License (ISCL)',
-        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
     ],
     keywords='paperspace api development library',
     packages=find_packages(exclude=['contrib', 'docs', 'tests']),
-    install_requires=['boto3', 'botocore', 'requests'],
-)
+    install_requires=['requests[security]', 'boto3', 'botocore'],
+)