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] <support@github.com>

Gemfile.lock

@@ -14,6 +14,7 @@ GEM
     connection_pool (2.4.1)
     domain_name (0.5.20190701)
       unf (>= 0.0.5, < 1.0.0)
+    ffi (1.15.5)
     ffi (1.15.5-x64-mingw32)
     ffi-compiler (1.0.1)
       ffi (>= 1.0.0)
@@ -37,7 +38,8 @@ GEM
     rainbow (3.0.0)
     rake (13.0.6)
     regexp_parser (2.1.1)
-    rexml (3.2.5)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
     rubocop (1.22.3)
       parallel (~> 1.10)
       parser (>= 3.0.0.0)
@@ -50,13 +52,16 @@ GEM
     rubocop-ast (1.13.0)
       parser (>= 3.0.1.1)
     ruby-progressbar (1.11.0)
+    strscan (3.1.0)
     unf (0.1.4)
       unf_ext
+    unf_ext (0.0.8.2)
     unf_ext (0.0.8.2-x64-mingw32)
     unicode-display_width (2.1.0)
 
 PLATFORMS
   x64-mingw32
+  x86_64-linux
 
 DEPENDENCIES
   expo-server-sdk!