build(deps): bump sqlite3 from 1.6.7 to 1.6.8

Bumps [sqlite3](https://github.com/sparklemotion/sqlite3-ruby) from 1.6.7 to 1.6.8.
- [Release notes](https://github.com/sparklemotion/sqlite3-ruby/releases)
- [Changelog](https://github.com/sparklemotion/sqlite3-ruby/blob/master/CHANGELOG.md)
- [Commits](sparklemotion/sqlite3-ruby@v1.6.7...v1.6.8)

---
updated-dependencies:
- dependency-name: sqlite3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -294,7 +294,7 @@ GEM
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
     smart_properties (1.17.0)
-    sqlite3 (1.6.7)
+    sqlite3 (1.6.8)
       mini_portile2 (~> 2.8.0)
     stringio (3.0.8)
     thor (1.3.0)