Update mechanize to version 2.7.6

Gemfile.lock

@@ -129,7 +129,7 @@ GEM
     devise-i18n (0.10.3)
     diff-lcs (1.3)
     docile (1.3.1)
-    domain_name (0.5.19)
+    domain_name (0.5.20180417)
       unf (>= 0.0.5, < 1.0.0)
     dotenv (0.9.0)
     dotenv-rails (0.9.0)
@@ -164,7 +164,7 @@ GEM
     gyoku (1.1.1)
       builder (>= 2.1.2)
     highline (2.0.0)
-    http-cookie (1.0.2)
+    http-cookie (1.0.3)
       domain_name (~> 0.5)
     httparty (0.13.3)
       json (~> 1.8)
@@ -214,13 +214,13 @@ GEM
       nokogiri (>= 1.5.9)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
-    mechanize (2.7.2)
+    mechanize (2.7.6)
       domain_name (~> 0.5, >= 0.5.1)
-      http-cookie (~> 1.0.0)
-      mime-types (~> 1.17, >= 1.17.2)
+      http-cookie (~> 1.0)
+      mime-types (>= 1.17.2)
       net-http-digest_auth (~> 1.1, >= 1.1.1)
-      net-http-persistent (~> 2.5, >= 2.5.2)
-      nokogiri (~> 1.4)
+      net-http-persistent (>= 2.5.2)
+      nokogiri (~> 1.6)
       ntlm-http (~> 0.1, >= 0.1.1)
       webrobots (>= 0.0.9, < 0.2)
     method_source (0.9.2)
@@ -235,10 +235,11 @@ GEM
       i18n (>= 0.6.4, <= 0.7.0)
     multi_json (1.13.1)
     multi_xml (0.5.5)
-    net-http-digest_auth (1.4)
-    net-http-persistent (2.9.4)
+    net-http-digest_auth (1.4.1)
+    net-http-persistent (3.0.0)
+      connection_pool (~> 2.2)
     newrelic_rpm (5.6.0.349)
-    nokogiri (1.10.0)
+    nokogiri (1.10.1)
       mini_portile2 (~> 2.4.0)
     nori (2.3.0)
     ntlm-http (0.1.1)
@@ -425,7 +426,7 @@ GEM
       execjs (>= 0.3.0, < 3)
     unf (0.1.4)
       unf_ext
-    unf_ext (0.0.6)
+    unf_ext (0.0.7.5)
     unicode-display_width (1.4.1)
     vcr (4.0.0)
     warden (1.2.7)
@@ -439,7 +440,7 @@ GEM
       binding_of_caller (>= 0.7.2)
       railties (~> 4.0)
       sprockets-rails (>= 2.0, < 4.0)
-    webrobots (0.1.1)
+    webrobots (0.1.2)
     whenever (0.9.0)
       activesupport (>= 2.3.4)
       chronic (>= 0.6.3)