Clean up compact index builder and remove schema.rb

Remove boilerplate comment placeholders from CompactIndexBuilder classes
and delete schema.rb file as requested in review comments.

Author: segiddins

lib/gemstash/compact_index_builder.rb

@@ -7,7 +7,6 @@
 require "zlib"
 
 module Gemstash
-  # Comment
   class CompactIndexBuilder
     include Gemstash::Env::Helper
     attr_reader :result
@@ -67,7 +66,6 @@ def check_auth
       @auth.check("fetch")
     end
 
-    # Comment
     class Versions < CompactIndexBuilder
       def fetch_resource
         storage.resource("versions")
@@ -163,7 +161,6 @@ def key
       end
     end
 
-    # Comment
     class Info < CompactIndexBuilder
       def initialize(auth, name)
         super(auth)
@@ -219,7 +216,6 @@ def key
       end
     end
 
-    # Comment
     class Names < CompactIndexBuilder
       def fetch_resource
         storage.resource("names")