Remove user parameter from call to `share_scheme`.

The current user (`ENV['USER']`) is already the default.

lib/cocoapods/installer.rb

@@ -615,7 +615,7 @@ module Pod
       end.flatten
 
       development_pod_targets.each do |pod_target|
-        Xcodeproj::XCScheme.share_scheme(pods_project.path, pod_target.name, ENV['USER'])
+        Xcodeproj::XCScheme.share_scheme(pods_project.path, pod_target.name)
       end
     end
 

spec/unit/installer_spec.rb

@@ -600,8 +600,7 @@ module Pod
 
           Xcodeproj::XCScheme.expects(:share_scheme).with(
             @installer.pods_project.path,
-            'Pods-default-BananaLib',
-            ENV['USER'])
+            'Pods-default-BananaLib')
 
           @installer.send(:share_development_pod_schemes)
         end