v3: add missing files

lib/travis/api/v3/queries/build.rb

@@ -0,0 +1,10 @@
+module Travis::API::V3
+  class Queries::Build < Query
+    params :id
+
+    def find
+      return ::Build.find_by_id(id) if id
+      raise WrongParams
+    end
+  end
+end

lib/travis/api/v3/renderer/build.rb

@@ -0,0 +1,8 @@
+require 'travis/api/v3/renderer/model_renderer'
+
+module Travis::API::V3
+  class Renderer::Build < Renderer::ModelRenderer
+    representation(:minimal,  :id, :number, :state, :duration, :started_at, :finished_at)
+    representation(:standard, *representations[:minimal], :repository)
+  end
+end