Remove 3.0 -> 3.2 support. Travis not supporting 3.0 and 3.1, and pip and requests lib not supporting 3.2

Updated readme with the supported versions

.travis.yml

@@ -1,9 +1,6 @@
 language: python
 python:
   - "2.7"
-  - "3.0"
-  - "3.1"
-  - "3.2"
   - "3.3"
   - "3.4"
   - "3.5"

README.md

@@ -13,6 +13,15 @@ In case the logs failed to be sent to Logz.io after a couple of tries, they will
 pip install logzio-python-handler
 ```
 
+## Tested Python Versions
+Travis CI will build this handler and test against:
+  - "2.7"
+  - "3.3"
+  - "3.4"
+  - "3.5"
+  - "3.6"
+We can't ensure compatibility to any other version, as we can't test it automatically.
+
 ## Python configuration
 #### Config File
 ```