Add a way fo force a test to be executed if a component is on a given branch

[cbeauchesne]

The idea is to solve the egg-chicken issue when somebody want to add a feature/fix in a component, and activate the test.

@branch(ruby="add-remote-config-or-whatever")

1. We get the repo name and the branch name threw env var (probably the simplest)
2. if the repo name and the branch name matches a @branch declaration, any @released, @bug declaration are ignored, and the test is executed

It will be used on distant repos, and totally ignored in nightly runs.

[cbeauchesne]

and unfortunately, it solves nothing, as we need to do a Pr on system tests after distant PR is merged :(

[cbeauchesne]

Implem idea :

• mount binaries folder inside runner container
• install git tools in runner container
• in runner, if /binaries/repo-name exists, get data from it

it'll saves any requirements from weblog container

[cbeauchesne]

won't do, in favor of #913 : it's too complicated, solving nothing.

#913 offer a gentle way to declare some arbitraries test to run.

A PR on system tests remain mandatories, version declarations remains the main way to activate tests.