Removal of components required for hybrid docker containers

[muthusk]

As a separate docker image is available for hybrid gateway , can this one be updated to include only components required for standalone?

[Ariemeth]

Since v2.2.0.0 the image size has ballooned from a 255 MB image, to a 1.43 GB image with version v2.3.2

[lonelycode]

2.3.2 Does only include the required components (we removed redis and nginx), it's still bigger because it needs dependencies for python and lua versions:

https://github.com/TykTechnologies/tyk-gateway-docker/blob/version/v2.3.2/Dockerfile

[mvdan]

@Ariemeth you might be interested in #7 too.