Add test for OPTIONS and HEAD requests with catch-all

This illustrates the issue described in ruby-grape#1056 by adding a options and
head request when the catch-all route is enabled.

spec/grape/api_spec.rb

@@ -3046,6 +3046,12 @@ def before
         get '/v2/hello'
         expect(last_response.status).to eq(200)
         expect(last_response.body).to eq('v2')
+        options '/v2/hello'
+        expect(last_response.status).to eq(200)
+        expect(last_response.body).to be_blank
+        head '/v2/hello'
+        expect(last_response.status).to eq(200)
+        expect(last_response.body).to be_blank
         get '/foobar'
         expect(last_response.status).to eq(404)
         expect(last_response.body).to eq('Unrecognized request path: foobar - /foobar')