upgrade awscli version

fixes jakejarvis#79

Dockerfile

@@ -11,7 +11,7 @@ LABEL homepage="https://jarv.is/"
 LABEL maintainer="Jake Jarvis <[email protected]>"
 
 # https://github.com/aws/aws-cli/blob/master/CHANGELOG.rst
-ENV AWSCLI_VERSION='1.18.14'
+ENV AWSCLI_VERSION='1.29.4'
 
 RUN pip install --quiet --no-cache-dir awscli==${AWSCLI_VERSION}