API: render name instead of first_name and last_name in user data

app/presenters/profile_presenter.rb

@@ -55,8 +55,7 @@ class ProfilePresenter < BasePresenter
 
   def base_api_json
     {
-      first_name:  first_name,
-      last_name:   last_name,
+      name:        [first_name, last_name].join(" ").presence,
       diaspora_id: diaspora_handle,
       avatar:      AvatarPresenter.new(@presentable).base_hash,
       tags:        tags.pluck(:name)

spec/integration/api/users_controller_spec.rb

@@ -229,8 +229,7 @@ describe Api::V1::UsersController do
         expect(user["birthday"]).to eq(new_birthday.iso8601)
         expect(user["location"]).to eq(new_location)
         expect(user["gender"]).to eq(new_gender)
-        expect(user["first_name"]).to eq(new_first_name)
-        expect(user["last_name"]).to eq(new_last_name)
+        expect(user["name"]).to eq("#{new_first_name} #{new_last_name}")
         expect(user["searchable"]).to eq(new_searchable)
         expect(user["show_profile_info"]).to eq(new_show_profile_info)
         expect(user["nsfw"]).to eq(new_nsfw)
@@ -547,8 +546,7 @@ describe Api::V1::UsersController do
   def confirm_common_profile_elements(json)
     expect(json).to have_key("guid")
     expect(json).to have_key("diaspora_id")
-    expect(json).to have_key("first_name")
-    expect(json).to have_key("last_name")
+    expect(json).to have_key("name")
     expect(json).to have_key("avatar")
     expect(json).to have_key("tags")
   end

spec/presenters/person_presenter_spec.rb

@@ -214,8 +214,7 @@ describe PersonPresenter do
   def confirm_common_profile_elements(profile_hash)
     expect(profile_hash).to have_key(:guid)
     expect(profile_hash).to have_key(:diaspora_id)
-    expect(profile_hash).to have_key(:first_name)
-    expect(profile_hash).to have_key(:last_name)
+    expect(profile_hash).to have_key(:name)
     expect(profile_hash).to have_key(:avatar)
     expect(profile_hash).to have_key(:tags)
   end