fix(tools): update git tools at startup

[psyray]

Fix #15

Read issue for details

As EyeWitness has been patched, the bug above should be fixed when you restart the celery container, but not ...
So I've added a condition, when directory exists, for every tool, to update it by git pulling

So now EyeWitness bug need a simple make stop, make restart to be fixed

I've also:

• silent the pip output that makes the status of the tools update not visible
• fixed a small path bug for gf, this could improve things because this fix prevent the tomnomnom gf pattern copy to fail

Tested and working