Bump rexml from 3.2.5 to 3.2.8

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.5 to 3.2.8.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.2.5...v3.2.8)

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

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

Gemfile.lock

@@ -170,7 +170,8 @@ GEM
       trailblazer-option (>= 0.1.1, < 0.2.0)
       uber (< 0.2.0)
     retriable (3.1.2)
-    rexml (3.2.5)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
     rouge (2.0.7)
     ruby2_keywords (0.0.5)
     rubyzip (2.3.2)
@@ -183,6 +184,8 @@ GEM
     simctl (1.6.8)
       CFPropertyList
       naturally
+    slack-notifier (2.4.0)
+    strscan (3.1.0)
     terminal-notifier (2.0.0)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
@@ -205,17 +208,25 @@ GEM
       colored2 (~> 3.1)
       nanaimo (~> 0.3.0)
       rexml (~> 3.2.4)
+    xcov (1.8.1)
+      fastlane (>= 2.141.0, < 3.0.0)
+      multipart-post
+      slack-notifier
+      terminal-table
+      xcodeproj
+      xcresult (~> 0.2.0)
     xcpretty (0.3.0)
       rouge (~> 2.0.7)
     xcpretty-travis-formatter (1.0.1)
       xcpretty (~> 0.2, >= 0.0.7)
     xcresult (0.2.1)
 
 PLATFORMS
-  x86_64-darwin-17
+  x86_64-linux
 
 DEPENDENCIES
   fastlane
+  xcov
   xcresult
 
 BUNDLED WITH