Bump sitemap_generator from 6.1.2 to 6.3.0

Bumps [sitemap_generator](https://github.com/kjvarga/sitemap_generator) from 6.1.2 to 6.3.0.
- [Release notes](https://github.com/kjvarga/sitemap_generator/releases)
- [Changelog](https://github.com/kjvarga/sitemap_generator/blob/master/CHANGES.md)
- [Commits](https://github.com/kjvarga/sitemap_generator/compare/v6.1.2...v6.3.0)

---
updated-dependencies:
- dependency-name: sitemap_generator
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Gemfile

@@ -51,7 +51,7 @@ gem "responders", "~> 3.0.1"
 gem "rinku", "~> 2.0.6", require: "rails_rinku"
 gem "sassc-rails", "~> 2.1.2"
 gem "savon", "~> 2.12.1"
-gem "sitemap_generator", "~> 6.1.2"
+gem "sitemap_generator", "~> 6.3.0"
 gem "social-share-button", "~> 1.2.4"
 gem "sprockets", "~> 4.1.1"
 gem "translator-text", "~> 0.1.0"

Gemfile.lock

@@ -611,7 +611,7 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    sitemap_generator (6.1.2)
+    sitemap_generator (6.3.0)
       builder (~> 3.0)
     smart_properties (1.15.0)
     social-share-button (1.2.4)
@@ -785,7 +785,7 @@ DEPENDENCIES
   savon (~> 2.12.1)
   scss_lint (~> 0.59.0)
   selenium-webdriver (~> 3.142)
-  sitemap_generator (~> 6.1.2)
+  sitemap_generator (~> 6.3.0)
   social-share-button (~> 1.2.4)
   spring (~> 2.1.1)
   spring-commands-rspec (~> 1.0.4)