Bump leaflet-rails from 1.0.3 to 1.5.1

Bumps [leaflet-rails](https://github.com/axyjo/leaflet-rails) from 1.0.3 to 1.5.1.
- [Release notes](https://github.com/axyjo/leaflet-rails/releases)
- [Commits](axyjo/leaflet-rails@v1.0.3...v1.5.1)

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

Author: dependabot-preview[bot]

Gemfile.lock

@@ -127,15 +127,15 @@ GEM
     json (2.2.0)
     launchy (2.4.3)
       addressable (~> 2.3)
-    leaflet-rails (1.0.3)
+    leaflet-rails (1.5.1)
       rails (>= 4.2.0)
     loofah (2.2.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
     method_source (0.9.2)
-    mini_mime (1.0.1)
+    mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
     multipart-post (2.1.1)