Update webmock to version 3.13.0

Gemfile.lock

@@ -136,8 +136,8 @@ GEM
     country_select (4.0.0)
       countries (~> 3.0)
       sort_alphabetical (~> 1.0)
-    crack (0.4.3)
-      safe_yaml (~> 1.0.0)
+    crack (0.4.5)
+      rexml
     crass (1.0.6)
     daemons (1.4.0)
     dalli (2.7.11)
@@ -220,7 +220,7 @@ GEM
       rake (>= 10, < 13)
       rubocop (>= 0.50.0)
       sysexits (~> 1.1)
-    hashdiff (0.3.7)
+    hashdiff (1.0.1)
     hashery (2.1.2)
     hashie (4.1.0)
     html2haml (2.2.0)
@@ -460,6 +460,7 @@ GEM
       http-cookie (>= 1.0.2, < 2.0)
       mime-types (>= 1.16, < 4.0)
       netrc (~> 0.8)
+    rexml (3.2.5)
     rolify (6.0.0)
     rqrcode (0.10.1)
       chunky_png (~> 1.0)
@@ -507,7 +508,6 @@ GEM
     ruby_parser (3.11.0)
       sexp_processor (~> 4.9)
     rubyzip (1.3.0)
-    safe_yaml (1.0.4)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
@@ -604,10 +604,10 @@ GEM
       nokogiri (~> 1.6)
       rubyzip (>= 1.3.0)
       selenium-webdriver (>= 3.0, < 4.0)
-    webmock (3.5.1)
+    webmock (3.13.0)
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
-      hashdiff
+      hashdiff (>= 0.4.0, < 2.0.0)
     websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)