Bump swh dependencies

to more reasonable versions...

requirements-swh-graph.txt

-swh.graph >= 0.3.2
+swh.graph >= 1

requirements-swh.txt

 swh.core[db,http] >= 2
-swh.model >= 3.0.0
-swh.objstorage >= 0.0.17
-swh.scheduler >= 0.7.0
-swh.storage >= 0.43.1
+swh.model >= 6
+swh.objstorage >= 2
+swh.scheduler >= 1.2
+swh.storage >= 1.3