Use my python3 fork of cfn_resource

this pip issue was not helpful in solving this.
pypa/setuptools#392

.travis.yml

@@ -1,7 +1,9 @@
 language: python
 python:
 - '3.6'
-install: pip install -r requirements.txt -t .
+install:
+- pip install -r requirements.txt -t .
+- wget https://raw.githubusercontent.com/tmclaugh/cfn-wrapper-python/python3/cfn_resource.py -O cfn_resource.py
 script:
 - true
 after_success: