add cable but not complete

Gemfile.lock

@@ -48,9 +48,9 @@ GEM
       sass (>= 3.4.19)
     builder (3.2.3)
     byebug (9.0.6)
-    coffee-rails (4.2.1)
+    coffee-rails (4.2.2)
       coffee-script (>= 2.2.0)
-      railties (>= 4.0.0, < 5.2.x)
+      railties (>= 4.0.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
@@ -97,7 +97,7 @@ GEM
     minitest (5.10.2)
     multi_json (1.12.1)
     mysql2 (0.4.6)
-    nio4r (2.0.0)
+    nio4r (2.1.0)
     nokogiri (1.7.2)
       mini_portile2 (~> 2.1.0)
     pdf-core (0.7.0)
@@ -238,6 +238,7 @@ DEPENDENCIES
   puma (~> 3.0)
   rack-cors
   rails (~> 5.1.0)
+  redis (~> 3.0)
   rspec-rails (~> 3.5)
   sass-rails (~> 5.0)
   schema_to_scaffold
@@ -255,4 +256,4 @@ DEPENDENCIES
   web-console (>= 3.3.0)
 
 BUNDLED WITH
-   1.14.6
+   1.15.0