Add java version to docker image tag name

[dortegau]

Prerequisites

• [ X ] Put an X between the brackets on this line if you have done all of the following:
  • Checked that your issue isn't already filled: https://github.com/issues?utf8=✓&q=is%3Aissue+user%3Aidealista
  • Checked that there is not already provided the described functionality

Description

IMHO the tag name should include installed java version number instead of role version name:

$ docker run -it idealista/jdk:3.3.0-debian9-openjdk /usr/bin/java -version
openjdk version "1.8.0_181"
OpenJDK Runtime Environment (build 1.8.0_181-8u181-b13-2~deb9u1-b13)
OpenJDK 64-Bit Server VM (build 25.181-b13, mixed mode)

Probably 3.3.0 is meaningless for the majority of java users and 1.8.0_181 should be used.

Note: The problem is to extract this version name, because in openjdk isn't explicitly specified. Related issue: #57