Merge pull request #29 from cloudfoundry-samples/dependabot/bundler/example_app/ffi-1.15.0

Bump ffi from 1.9.18 to 1.15.0 in /example_app

Author: elenasharma

example_app/Gemfile.lock

@@ -17,7 +17,7 @@ GEM
     coderay (1.1.2)
     faraday (0.13.1)
       multipart-post (>= 1.2, < 3)
-    ffi (1.9.18)
+    ffi (1.15.0)
     listen (3.1.5)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)