updated atom-beta (1.8.0-beta0) (#1910)

Casks/atom-beta.rb

@@ -1,11 +1,11 @@
 cask 'atom-beta' do
-  version '1.7.0-beta5'
+  version '1.8.0-beta0'
-  sha256 '895136b558a47bc778bc1b20a2be1c1edb8122d4302fa6828494b2922753c7dc'
+  sha256 'ae49d5e638b6f6520fef91832a9d83ac5f78b1acf936821e5f660995d9b11c31'
 
   # github.com/atom/atom was verified as official when first introduced to the cask
   url "https://github.com/atom/atom/releases/download/v#{version}/atom-mac.zip"
   appcast 'https://github.com/atom/atom/releases.atom',
-          checkpoint: '32bf708ffc64cfb4db74b4cfc04320ea0f0c2d7585c6bb732bef2f792e9144c4'
+          checkpoint: 'af7b24046c3d9bd1d97870e1bcff743889349dd9238a60900350eba888e31d54'
   name 'Github Atom Beta'
   homepage 'https://atom.io/beta'
   license :mit