Add capistrano and deploy configs for staging.

Gemfile.lock

@@ -62,12 +62,27 @@ GEM
       zeitwerk (~> 2.2, >= 2.2.2)
     addressable (2.7.0)
       public_suffix (>= 2.0.2, < 5.0)
+    airbrussh (1.4.0)
+      sshkit (>= 1.6.1, != 1.7.0)
     bcrypt (3.1.15)
     bindex (0.8.1)
     bootsnap (1.4.8)
       msgpack (~> 1.0)
     builder (3.2.4)
     byebug (11.1.3)
+    capistrano (3.14.1)
+      airbrussh (>= 1.0.0)
+      i18n
+      rake (>= 10.0.0)
+      sshkit (>= 1.9.0)
+    capistrano-bundler (2.0.1)
+      capistrano (~> 3.1)
+    capistrano-rails (1.6.1)
+      capistrano (~> 3.1)
+      capistrano-bundler (>= 1.1, < 3)
+    capistrano-rvm (0.1.2)
+      capistrano (~> 3.0)
+      sshkit (~> 1.2)
     capybara (3.33.0)
       addressable
       mini_mime (>= 0.1.3)
@@ -141,6 +156,9 @@ GEM
     multi_xml (0.6.0)
     multipart-post (2.1.1)
     nested_form (0.3.2)
+    net-scp (3.0.0)
+      net-ssh (>= 2.6.5, < 7.0.0)
+    net-ssh (6.1.0)
     nio4r (2.5.2)
     nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
@@ -262,6 +280,9 @@ GEM
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)
+    sshkit (1.21.0)
+      net-scp (>= 1.1.2)
+      net-ssh (>= 2.8.0)
     temple (0.8.2)
     thor (1.0.1)
     thread_safe (0.3.6)
@@ -302,6 +323,9 @@ PLATFORMS
 DEPENDENCIES
   bootsnap (>= 1.4.2)
   byebug
+  capistrano (~> 3.10)
+  capistrano-rails (~> 1.3)
+  capistrano-rvm
   capybara (>= 2.15)
   devise (~> 4.7)
   devise-bootstrap-views (~> 1.0)