fix(ci): properly removing docker volumes

Laurent noticed it on one of his MR and confirmed with him:
  -- Volumes have be created the 1st time they ran on avra on July 7th
  -- Volumes were created with not only the raw files but also the nr-softmodem executable

Solution: two-fold:
  1. using the `docker-compose down -v` syntax, the volume is deleted automatically
  2. I added redundancy with the custom command to remove the used volume

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

ci-scripts/ran.py

@@ -260,6 +260,7 @@ class RANManagement():
 		self.checkBuildeNB(lIpAddr, lUserName, lPassWord, lSourcePath, self.backgroundBuildTestId[int(self.eNB_instance)], HTML)
 
 	def CustomCommand(self, HTML):
+		logging.info(f"Executing custom command on {self.node}")
 		cmd = cls_cmd.getConnection(self.node)
 		ret = cmd.run(self.command)
 		cmd.close()