test: ensure RspecApiDocumentation.configuration.app is set

@@ -12,6 +12,12 @@
 resource "Order" do
 explanation "Order resource explanation"
 
+let(:context) { |example| double(:app => StubApp, :example => example) }
+
+before do
+RspecApiDocumentation.configuration.app ||= context.app
+end
+
 describe "example metadata" do
 subject { |example| example.metadata }
 

@@ -9,6 +9,10 @@
 
 subject { test_client }
 
+before do
+RspecApiDocumentation.configuration.app ||= context.app
+end
+
 it { expect(subject).to be_a(RspecApiDocumentation::RackTestClient) }
 
 its(:context) { should equal(context) }