Sync3n Initial Add

MANIFEST.in

@@ -17,6 +17,7 @@ recursive-include docs *.rst
 recursive-include docs Makefile
 recursive-include docs *.sh
 recursive-include src *.conf
+recursive-include src *.cu
 recursive-include src *.yaml
 prune docs/build
 prune docs/source

src/aspire/abinitio/__init__.py

@@ -4,6 +4,7 @@
 
 # isort: off
 from .commonline_sync import CLSyncVoting
+from .commonline_sync3n import CLSync3N
 from .commonline_c3_c4 import CLSymmetryC3C4
 from .commonline_cn import CLSymmetryCn
 from .commonline_c2 import CLSymmetryC2