Create credits database file’s enclosing directory as necessary

bin/gen_credits.rb

@@ -6,6 +6,7 @@
 $KCODE = 'U' if RUBY_VERSION < "1.9"
 
 require 'digest/md5'
+require 'fileutils'
 require 'net/https'
 require 'uri'
 require 'cgi'
@@ -21,7 +22,8 @@ require 'set'
 class GitHubLookup
 
   def self.initialize(dbm_file)
-    @db = DBM.new(dbm_file)
+    FileUtils.mkdir_p(File.dirname(dbm_file))
+    @db = DBM.new(dbm_file, 0644, DBM::WRCREAT)
     # seed with some contributors that don't have an email
     # address assigned publicly in their account
     @db['1178ce2f664a6cee9a05a3e11af5d8d2'] = 'aaronbrethorst'