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](https://github.com/sparklemotion/sqlite3-ruby/compare/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

@@ -7,7 +7,7 @@ GEM
       oauth
     flickraw (0.9.10)
     method_source (1.0.0)
-    mini_portile2 (2.8.4)
+    mini_portile2 (2.8.5)
     multi_json (1.15.0)
     mustermann (2.0.2)
       ruby2_keywords (~> 0.0.1)
@@ -39,7 +39,7 @@ GEM
     sinatra-sequel (0.9.0)
       sequel (>= 3.2.0)
       sinatra (>= 0.9.4)
-    sqlite3 (1.6.7)
+    sqlite3 (1.6.8)
       mini_portile2 (~> 2.8.0)
     tilt (2.0.11)
     webrick (1.7.0)