pin old sprockets

As is traditional for every Rails point release, the asset pipeline broke in a
new and obtuse way. In this case, by hanging puma indefinitely after serving
any page, requiring a kill -9. Pinning an old version; I'll burn 20 hours
unfucking whatever new wrong thing it's doing later.

The asset pipeline is nine years old.

Gemfile

@@ -11,6 +11,7 @@ gem "mysql2"
 gem 'scenic'
 gem 'scenic-mysql_adapter'
 gem "activerecord-typedstore"
+gem 'sprockets-rails', '2.3.3'
 
 # js
 gem "dynamic_form"
@@ -21,7 +22,7 @@ gem "uglifier", ">= 1.3.0"
 # deployment
 gem "actionpack-page_caching"
 gem "exception_notification"
-gem "unicorn"
+gem "puma"
 
 # security
 gem "bcrypt", "~> 3.1.2"

Gemfile.lock

@@ -102,7 +102,6 @@ GEM
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
     json (2.3.0)
-    kgio (2.11.3)
     listen (3.2.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
@@ -133,6 +132,8 @@ GEM
       ruby-rc4
       ttfunk
     public_suffix (4.0.5)
+    puma (4.3.4)
+      nio4r (~> 2.0)
     rack (2.2.2)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -161,7 +162,6 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.19.0, < 2.0)
     rainbow (3.0.0)
-    raindrops (0.19.1)
     rake (13.0.1)
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
@@ -222,13 +222,13 @@ GEM
       parser
     sitemap_generator (6.1.0)
       builder (~> 3.0)
-    sprockets (4.0.0)
+    sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.2.1)
-      actionpack (>= 4.0)
-      activesupport (>= 4.0)
-      sprockets (>= 3.0.0)
+    sprockets-rails (2.3.3)
+      actionpack (>= 3.0)
+      activesupport (>= 3.0)
+      sprockets (>= 2.8, < 4.0)
     thor (1.0.1)
     thread_safe (0.3.6)
     transaction_isolation (1.0.5)
@@ -242,9 +242,6 @@ GEM
     uglifier (4.2.0)
       execjs (>= 0.3.0, < 3)
     unicode-display_width (1.7.0)
-    unicorn (5.5.5)
-      kgio (~> 2.6)
-      raindrops (~> 0.7)
     uniform_notifier (1.13.0)
     websocket-driver (0.7.1)
       websocket-extensions (>= 0.1.0)
@@ -278,6 +275,7 @@ DEPENDENCIES
   nokogiri (>= 1.10.8)
   oauth
   pdf-reader
+  puma
   rails (~> 5.2.4.3)
   rb-readline
   rotp
@@ -291,9 +289,9 @@ DEPENDENCIES
   scenic-mysql_adapter
   scout_apm (= 2.6.2)
   sitemap_generator
+  sprockets-rails (= 2.3.3)
   transaction_retry
   uglifier (>= 1.3.0)
-  unicorn
 
 BUNDLED WITH
    2.1.4

app/assets/config/manifest.js

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

config/initializers/assets.rb

@@ -1,7 +1,7 @@
 # Be sure to restart your server when you modify this file.
 
 # Version of your assets, change this if you want to expire all your assets.
-Rails.application.config.assets.version = '1.0'
+Rails.application.config.assets.version = '2.0'
 
 # Add additional assets to the asset load path.
 # Rails.application.config.assets.paths << Emoji.images_path