Bump letter_opener from 1.7.0 to 1.10.0

Bumps [letter_opener](https://github.com/ryanb/letter_opener) from 1.7.0 to 1.10.0.
- [Changelog](https://github.com/ryanb/letter_opener/blob/master/CHANGELOG.md)
- [Commits](ryanb/letter_opener@v1.7.0...v1.10.0)

---
updated-dependencies:
- dependency-name: letter_opener
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -77,6 +77,8 @@ GEM
       bundler (>= 1.2.0, < 3)
       thor (~> 1.0)
     byebug (11.1.3)
+    childprocess (5.1.0)
+      logger (~> 1.5)
     concurrent-ruby (1.3.4)
     connection_pool (2.4.1)
     crass (1.0.6)
@@ -110,14 +112,16 @@ GEM
       concurrent-ruby (~> 1.0)
     jbuilder (2.11.2)
       activesupport (>= 5.0.0)
-    launchy (2.5.0)
-      addressable (~> 2.7)
-    letter_opener (1.7.0)
-      launchy (~> 2.2)
+    launchy (3.0.1)
+      addressable (~> 2.8)
+      childprocess (~> 5.0)
+    letter_opener (1.10.0)
+      launchy (>= 2.2, < 4)
     listen (3.6.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     lockbox (1.4.0)
+    logger (1.6.1)
     loofah (2.22.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)