New armhf and updated sample function Dockerfiles

Signed-off-by: rgee0 <richard@technologee.co.uk>

Bump armhf Gateway to 0.6.0

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: John McCabe <john@johnmccabe.net>

Signed-off-by: Steve Lacy <me@slacy.me>

Export struct members of GatewayConfig{}

Add env configurable readTimeout / writeTimeout
Add env-timeout test
Modify appropriate Dockerfiles

Signed-off-by: leigh schrandt <leigh@null.net>