init fixes (git, pip & test related)

- gitignored: *.pyc, env/
  - gevent added to requirements.txt
  - test_httpbin syntax error fix

.gitignore

@@ -1,2 +1,4 @@
+env/
 .workon
-.epio-app
+.epio-app
+*.pyc

requirements.txt

@@ -13,3 +13,4 @@ newrelic==1.2.1.265
 raven==1.9.3
 simplejson==2.4.0
 wsgiref==0.1.2
+gevent

test_httpbin.py

@@ -21,7 +21,7 @@ class HttpbinTestCase(unittest.TestCase):
     def test_base64(self):
         greeting = u'Здравствуй, мир!'
         b64_encoded = _string_to_base64(greeting)
-        response = self.app.get('/base64/{}'.format(b64_encoded))
+        response = self.app.get('/base64/{0}'.format(b64_encoded))
         content = response.data.decode('utf-8')
         self.assertEquals(greeting, content)