Bump tzinfo-data from 1.2018.5 to 1.2018.7

Bumps [tzinfo-data](https://github.com/tzinfo/tzinfo-data) from 1.2018.5 to 1.2018.7.
- [Release notes](https://github.com/tzinfo/tzinfo-data/releases)
- [Commits](tzinfo/tzinfo-data@v1.2018.5...v1.2018.7)

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

Gemfile.lock

@@ -364,7 +364,7 @@ GEM
     turbolinks-source (5.2.0)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
-    tzinfo-data (1.2018.5)
+    tzinfo-data (1.2018.7)
       tzinfo (>= 1.0.0)
     unicode-display_width (1.3.0)
     uniform_notifier (1.11.0)