Add mailgun-ruby dependency

Gemfile

@@ -40,6 +40,8 @@ gem 'interactor-rails'
 
 gem 'active_model_serializers'
 
+gem 'mailgun-ruby'
+
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug', platforms: %i[mri mingw x64_mingw]

Gemfile.lock

@@ -76,6 +76,8 @@ GEM
       rails (>= 4.2.0, < 6)
     diff-lcs (1.3)
     docile (1.3.1)
+    domain_name (0.5.20180417)
+      unf (>= 0.0.5, < 1.0.0)
     erubi (1.8.0)
     factory_bot (5.0.2)
       activesupport (>= 4.2.0)
@@ -88,6 +90,8 @@ GEM
     globalid (0.4.2)
       activesupport (>= 4.2.0)
     htmlentities (4.3.4)
+    http-cookie (1.0.3)
+      domain_name (~> 0.5)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
     interactor (3.1.1)
@@ -107,14 +111,20 @@ GEM
       nokogiri (>= 1.5.9)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
+    mailgun-ruby (1.1.11)
+      rest-client (~> 2.0.2)
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (0.9.2)
+    mime-types (3.2.2)
+      mime-types-data (~> 3.2015)
+    mime-types-data (3.2019.0331)
     mimemagic (0.3.3)
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
     msgpack (1.2.9)
+    netrc (0.11.0)
     nio4r (2.3.1)
     nokogiri (1.10.2)
       mini_portile2 (~> 2.4.0)
@@ -162,6 +172,10 @@ GEM
     responders (2.4.1)
       actionpack (>= 4.2.0, < 6.0)
       railties (>= 4.2.0, < 6.0)
+    rest-client (2.0.2)
+      http-cookie (>= 1.0.2, < 2.0)
+      mime-types (>= 1.16, < 4.0)
+      netrc (~> 0.8)
     reverse_markdown (1.1.0)
       nokogiri
     rspec-core (3.8.0)
@@ -230,6 +244,9 @@ GEM
     tins (1.20.2)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
+    unf (0.1.4)
+      unf_ext
+    unf_ext (0.0.7.6)
     unicode-display_width (1.5.0)
     warden (1.2.8)
       rack (>= 2.0.6)
@@ -253,6 +270,7 @@ DEPENDENCIES
   interactor
   interactor-rails
   listen (>= 3.0.5, < 3.2)
+  mailgun-ruby
   pg
   puma (~> 3.11)
   rack-cors