Add pre-built binaries for mandb and nginx (#3506)

Update mandb to 2.8.6.1

packages/mandb.rb

@@ -8,8 +8,16 @@ class Mandb < Package
   source_sha256 '2c77a2bb9dbf06f72417a6f63063e204888a22a5020ff77334d304d55f813a28'
 
   binary_url ({
+    aarch64: 'https://dl.bintray.com/chromebrew/chromebrew/mandb-2.8.6.1-chromeos-armv7l.tar.xz',
+     armv7l: 'https://dl.bintray.com/chromebrew/chromebrew/mandb-2.8.6.1-chromeos-armv7l.tar.xz',
+       i686: 'https://dl.bintray.com/chromebrew/chromebrew/mandb-2.8.6.1-chromeos-i686.tar.xz',
+     x86_64: 'https://dl.bintray.com/chromebrew/chromebrew/mandb-2.8.6.1-chromeos-x86_64.tar.xz',
   })
   binary_sha256 ({
+    aarch64: '4ab54543270e692f94ac50235b1518824aa1bdb09a45745991848e9c30dc6469',
+     armv7l: '4ab54543270e692f94ac50235b1518824aa1bdb09a45745991848e9c30dc6469',
+       i686: 'c8378e0ca6622c336bf3e8cfab8a85aff1f49a498008221a06be74dc5509311d',
+     x86_64: '5d830ca395acb5b7ab78fef4e44669bc1c5066196d139bcfcabd91c5b51055a8',
   })
 
   def self.build

packages/nginx.rb

@@ -8,8 +8,16 @@ class Nginx < Package
   source_sha256 '62854b365e66670ef4f1f8cc79124f914551444da974207cd5fe22d85710e555'
 
   binary_url ({
+    aarch64: 'https://dl.bintray.com/chromebrew/chromebrew/nginx-1.17.4-chromeos-armv7l.tar.xz',
+     armv7l: 'https://dl.bintray.com/chromebrew/chromebrew/nginx-1.17.4-chromeos-armv7l.tar.xz',
+       i686: 'https://dl.bintray.com/chromebrew/chromebrew/nginx-1.17.4-chromeos-i686.tar.xz',
+     x86_64: 'https://dl.bintray.com/chromebrew/chromebrew/nginx-1.17.4-chromeos-x86_64.tar.xz',
   })
   binary_sha256 ({
+    aarch64: 'f67f978ee52a403fb628c0d4128c01a0b556974d4a573afd1ae3f3228c5e3f72',
+     armv7l: 'f67f978ee52a403fb628c0d4128c01a0b556974d4a573afd1ae3f3228c5e3f72',
+       i686: '04adfd5c84292dfeb788a982d970373b786ec511710083bb0f1611bcb359a630',
+     x86_64: '25c755241869d55397734f97bc1ee96ad36fd028315f5ffd151eabda7c66de5e',
   })
 
   depends_on 'pcre'