[merge_shared_tree|Coq]WIP: add the generator of contract

Status Job ID Name Coverage
  Build
failed #307566007
coq:8.8

00:04:01

failed #307566009
coq:8.9

00:03:44

 
Name Stage Failure
failed
coq:8.9 Build
+- The following changes have been performed
| - install coq-ott 0.29
| - install ott 0.29
+-
[NOTE] Pinning command successful, but your installed packages may be out of sync.

The former state can be restored with:
opam switch import "/home/coq/.opam/4.05.0/.opam-switch/backup/state-20190930095157.export"
ERROR: Job failed: exit code 1
failed
coq:8.8 Build
+- The following changes have been performed
| - install coq-ott 0.29
| - install ott 0.29
+-
[NOTE] Pinning command successful, but your installed packages may be out of sync.

The former state can be restored with:
opam switch import "/home/coq/.opam/4.05.0/.opam-switch/backup/state-20190930095206.export"
ERROR: Job failed: exit code 1