Remove the .opam files from version control, since they are generated…

… from dune-project.

Release v1.7.0.

Release 1.6.9

CHANGES:

- [bug] Fix multiline string support (#81)

Merge pull request #76 from liyishuai/patch

Allow empty patch version

Distribution v1.6.7

CHANGES:

- [compat] Treat ~ and - the same in semver in order to parse
           OCaml 4.12.0 pre-release versions.
- [compat] Restore 4.02.3 compatibility.

Distribution v1.6.6

Update change log

Version 1.6.4

Release 1.6.3

Merge pull request #53 from rgrinberg/promote-tests

Promote tests