Upgraded [foreman, sprockets, zeitwerk] gems

Gemfile.lock

@@ -119,7 +119,6 @@ GEM
     debug_inspector (0.0.3)
     diff-lcs (1.3)
     docile (1.3.2)
-    dotenv (0.7.0)
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
@@ -127,9 +126,7 @@ GEM
     eventmachine (1.2.7)
     execjs (2.7.0)
     ffi (1.11.1)
-    foreman (0.64.0)
+    foreman (0.86.0)
-      dotenv (~> 0.7.0)
-      thor (>= 0.13.6)
     formatador (0.2.5)
     gherkin (5.1.0)
     globalid (0.4.2)
@@ -309,7 +306,7 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    sprockets (3.7.2)
+    sprockets (4.0.0)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (3.2.1)
@@ -343,7 +340,7 @@ GEM
     websocket-extensions (0.1.4)
     xpath (3.2.0)
       nokogiri (~> 1.8)
-    zeitwerk (2.1.10)
+    zeitwerk (2.2.0)
 
 PLATFORMS
   ruby

app/assets/config/manifest.js

@@ -0,0 +1,3 @@
+//= link_tree ../images
+//= link_directory ../javascripts .js
+//= link_directory ../stylesheets .css