Merge pull request #1706 from caskroom/cask-repair_update-rstudio-preview

updated rstudio-preview (0.99.878)

Casks/rstudio-preview.rb

@@ -1,9 +1,9 @@
 cask 'rstudio-preview' do
-  version :latest
-  sha256 :no_check
+  version '0.99.878'
+  sha256 'fc8019678ae647c3f5d8d7a583fd6d40cf599cc5c056c51d68f2243c5472031b'
 
-  # rstudio.org is the official download host per the vendor homepage
-  url 'https://www.rstudio.org/download/latest/preview/desktop/mac/RStudio-latest.dmg'
+  # amazonaws.com/rstudio-dailybuilds was verified as official when first introduced to the cask
+  url "https://s3.amazonaws.com/rstudio-dailybuilds/RStudio-#{version}.dmg"
   name 'RStudio'
   homepage 'http://www.rstudio.com/ide/download/preview'
   license :affero