Add bash_completion postinstall method (#2099)

* Add postinstall method

* Update bash_completion to 2.8

packages/bash_completion.rb

@@ -3,21 +3,13 @@ require 'package'
 class Bash_completion < Package
   description 'Programmable completion functions for bash'
   homepage 'https://github.com/scop/bash-completion'
-  version '2.7-1'
-  source_url 'https://github.com/scop/bash-completion/archive/2.7.tar.gz'
-  source_sha256 'dba2b88c363178622b61258f35d82df64dc8d279359f599e3b93eac0375a416c'
+  version '2.8'
+  source_url 'https://github.com/scop/bash-completion/archive/2.8.tar.gz'
+  source_sha256 'c3f1bacac64bc69e3dfb9b1ef79ddbf755aac441b452845531950f1643bed25f'
 
   binary_url ({
-    aarch64: 'https://dl.bintray.com/chromebrew/chromebrew/bash_completion-2.7-1-chromeos-armv7l.tar.xz',
-     armv7l: 'https://dl.bintray.com/chromebrew/chromebrew/bash_completion-2.7-1-chromeos-armv7l.tar.xz',
-       i686: 'https://dl.bintray.com/chromebrew/chromebrew/bash_completion-2.7-1-chromeos-i686.tar.xz',
-     x86_64: 'https://dl.bintray.com/chromebrew/chromebrew/bash_completion-2.7-1-chromeos-x86_64.tar.xz',
   })
   binary_sha256 ({
-    aarch64: '486ae7b4f7a8748dbb624eb0a83d7c54dcff3f95151fb202cb905e24b1c4546d',
-     armv7l: '486ae7b4f7a8748dbb624eb0a83d7c54dcff3f95151fb202cb905e24b1c4546d',
-       i686: 'dc0d6a60d98556ab3baa967a06058daa6199d26b1667c07f39c6ae6263ce8602',
-     x86_64: '7e9cfea615bab8620a01384ee1e96c17218efa00bea1b7415c7680107a58cac2',
   })
 
   depends_on 'autoconf'
@@ -31,11 +23,14 @@ class Bash_completion < Package
 
   def self.install
     system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+  end
+
+  def self.postinstall
     puts
     puts "To complete installation, execute the following:".lightblue
     puts "echo '# bash completion' >> ~/.bashrc".lightblue
     puts "echo '[[ $PS1 && -f /usr/local/share/bash-completion/bash_completion ]] && \\' >> ~/.bashrc".lightblue
-    puts "echo '. /usr/local/share/bash-completion/bash_completion' >> ~/.bashrc".lightblue
+    puts "echo '    . /usr/local/share/bash-completion/bash_completion' >> ~/.bashrc".lightblue
     puts "source ~/.bashrc".lightblue
     puts
   end