Modify packages depends on `python`. Now they uses `python27`.

packages/aws.rb

@@ -7,7 +7,7 @@ class Aws < Package
   source_url 'https://github.com/aws/aws-cli/archive/1.11.121.tar.gz'
   source_sha256 'c667e77880a093d5ef3d635f19e7eab3cb0b7527f648d74e571fca8d170474a8'
 
-  depends_on 'python' unless File.exists? '/usr/local/bin/python'
+  depends_on 'python27' unless File.exists? '/usr/local/bin/python'
   depends_on 'unzip'
 
   def self.install

packages/dropbox.rb

@@ -15,7 +15,7 @@ class Dropbox < Package
     puts 'Unable to install dropboxd.  Supported architectures include x86 and x86_64 only.'.lightred
   end
 
-  depends_on 'python' unless File.exists? '/usr/local/bin/python'
+  depends_on 'python27' unless File.exists? '/usr/local/bin/python'
 
   def self.install
     system "wget https://linux.dropbox.com/packages/dropbox.py"

packages/ranger.rb

@@ -9,7 +9,7 @@ class Ranger < Package # the name of the package
 
   depends_on 'less'
   depends_on 'ncurses'
-  depends_on 'python'
+  depends_on 'python27'
 
   def self.build
    system "make"