Bump webmock from 3.5.1 to 3.8.1 (pay-rails#112)

Bumps [webmock](https://github.com/bblimke/webmock) from 3.5.1 to 3.8.1.
- [Release notes](https://github.com/bblimke/webmock/releases)
- [Changelog](https://github.com/bblimke/webmock/blob/master/CHANGELOG.md)
- [Commits](bblimke/webmock@v3.5.1...v3.8.1)

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

Co-authored-by: Chris Oliver <[email protected]>

Gemfile.lock

@@ -48,8 +48,8 @@ GEM
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
-    addressable (2.6.0)
-      public_suffix (>= 2.0.2, < 4.0)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
     arel (9.0.0)
     ast (2.4.0)
     braintree (2.96.0)
@@ -65,7 +65,7 @@ GEM
     erubi (1.8.0)
     globalid (0.4.2)
       activesupport (>= 4.2.0)
-    hashdiff (0.3.9)
+    hashdiff (1.0.0)
     i18n (1.8.2)
       concurrent-ruby (~> 1.0)
     jaro_winkler (1.5.4)
@@ -95,7 +95,7 @@ GEM
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
-    public_suffix (3.0.3)
+    public_suffix (4.0.3)
     rack (2.0.8)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -156,10 +156,10 @@ GEM
       thread_safe (~> 0.1)
     unicode-display_width (1.6.1)
     vcr (5.1.0)
-    webmock (3.5.1)
+    webmock (3.8.1)
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
-      hashdiff
+      hashdiff (>= 0.4.0, < 2.0.0)
     websocket-driver (0.7.1)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.4)