[Nexus] added slf4j to MANIFEST.MF dependencies
[Nexus] added slf4j to MANIFEST.MF dependencies

Signed-off-by: Matthew Dickie <82dca48737570b4f49d59ca286b5034c15e72ebc@diamond.ac.uk>
DawnScience/dawnsci,jamesmudd/dawnsci,eclipse/dawnsci,belkassaby/dawnsci,colinpalmer/dawnsci,colinpalmer/dawnsci,jamesmudd/dawnsci,xen-0/dawnsci,jamesmudd/dawnsci