Update smtpapi to 0.3.1

This updates the Python smtpapi library to 0.3.1, the latest version that has been released.

This closes #160.

Author: kevin-brown

setup.py

@@ -7,7 +7,7 @@
 
 
 def getRequires():
-    deps = ['smtpapi==0.2.0']
+    deps = ['smtpapi==0.3.1']
     if sys.version_info < (2, 7):
         deps.append('unittest2')
     elif (3, 0) <= sys.version_info < (3, 2):