Bump omniauth from 1.9.1 to 1.9.2

Bumps [omniauth](https://github.com/omniauth/omniauth) from 1.9.1 to 1.9.2.
- [Release notes](https://github.com/omniauth/omniauth/releases)
- [Commits](omniauth/omniauth@v1.9.1...v1.9.2)

---
updated-dependencies:
- dependency-name: omniauth
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -227,7 +227,7 @@ GEM
       racc (~> 1.4)
     nulldb (0.3.7.pre.alpha.1)
       activerecord (>= 2.0.0)
-    omniauth (1.9.1)
+    omniauth (1.9.2)
       hashie (>= 3.4.6)
       rack (>= 1.6.2, < 3)
     omniauth-cas (2.0.0)