Restore the custom naming based on config location

[jocgir]

The initial goal was to easily identify custom images instead of just having an anonymous hash to identify them. We then added a hash to ensure that we rebuild the image if the custom DockerFile or the custom build folder content changed and finally, we removed the name, thus loosing the identification of the custom image and returning to an anonymous image as we did originally.

It is still important to not rebuild the custom image if there is no change and rebuild it if there is a change. So, I simply added the hash into a label and instead putting the hash into the name, we simply check if the label has changed to determine if the image should be rebuilt.

[julienduchesne]

Fix the failing test. I verify the image name. Should be back to the directory name instead of the hash.

[coveralls]

Pull Request Test Coverage Report for Build 694

• 1 of 20 (5.0%) changed or added relevant lines in 2 files are covered.
• 10 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-1.4%) to 15.47%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
docker.go	0	19	0.0%

Files with Coverage Reduction	New Missed Lines	%
config.go	10	46.55%

Totals
Change from base Build 689:	-1.4%
Covered Lines:	140
Relevant Lines:	905

---

💛 - Coveralls