Remove broken scala-ide-nightly cask

I am an idiot. The url was for the Eclipse update site, not a
direct download. My sincerest apologies.

Casks/scala-ide-nightly.rb

@@ -1,13 +0,0 @@
-cask :v1 => 'scala-ide-nightly' do
-  version :latest
-  sha256 :no_check
-
-  url "http://download.scala-ide.org/nightly-scala-ide-4.0.x-211x.zip"
-  homepage 'http://scala-ide.org/'
-  license :bsd
-
-  # Renamed for clarity: app name is inconsistent with its branding.
-  # Also renamed to avoid conflict with other eclipse Casks.
-  # Original discussion: https://github.com/caskroom/homebrew-cask/pull/2731
-  app 'eclipse/Eclipse.app', :target => 'Scala IDE.app'
-end