Revert "Favor uname over user_agent"

This reverts commit 97931ceaed.

app/decorators/asciicast_decorator.rb

@@ -5,10 +5,10 @@ class AsciicastDecorator < ApplicationDecorator
   THUMBNAIL_HEIGHT = 10
 
   def os
-    if uname.present?
-      os_from_uname
-    elsif user_agent.present?
+    if user_agent.present?
       os_from_user_agent
+    elsif uname.present?
+      os_from_uname
     else
       'unknown'
     end

spec/decorators/asciicast_decorator_spec.rb

@@ -86,15 +86,6 @@ describe AsciicastDecorator do
 
       it { should == 'unknown' }
     end
-
-    context 'when user_agent and uname are present' do
-      before do
-        asciicast.user_agent = 'python-requests/2.0.0 CPython/2.7.5 Linux/3.11.3-201.fc19.x86_64'
-        asciicast.uname = 'Some t430u 3.5.0-18-generic #29-Ubuntu SMP'
-      end
-
-      it { should == 'Some' }
-    end
   end
 
   describe '#terminal_type' do