Add caution for Python3.5

Author: alehander92

README.md

@@ -7,6 +7,9 @@ A restricted Python to idiomatic JavaScript / Ruby / Go / C# translator
 
 [Pseudo](https://github.com/alehander42/pseudo) is a framework for high level code generation: it is used by this compiler to translate a subset of Python to all Pseudo-supported languages
 
+**If you are using Python3.5 and you experience problems with an already installed version of pseudo-python, please upgrade it to `0.2.8` (`pip3 install pseudo-python --upgrade`)**
+
+
 ## Supported subset
 
 Pseudo-Python compiles to `pseudo ast`.