ligo_v1.6.0

[frankhillard]

Support of ligo compiler v1.6.0
Use Tezos.Next and Test.Next for future migration.

There is a warning left

File "lib/fa2.1/entrypoints/lambda_export.jsligo", line 120, characters 17-38:
119 |          let combinedOps = list([...ops, ...ticketOps]);
120 |          return [list([ticket, ...lt]), updatedLedger, updatedStorage, combinedOps];
121 |       },
:
Warning: variable cannot be used more than once.

[rinderknecht]

LGTM