Update text on Docker HUB

[szabgab]

Recently as I looked at https://hub.docker.com/r/perldocker/perl-tester I saw on the main page (Overview) only older versions of perl (no 5.4x). It was confusing till I ran a search in the tags where I found the real tags.

I wonder if the "Overview" could be updated, or if it needs manual work them maybe its should be shortened and all the information should be in the README of this repository where it is easier to update.

[szabgab]

It seems that this PR: #43 tried to do the automatic update.

[oalders]

I think there is some kind of permissions issue here regarding Docker Hub that we were not able to overcome.