Resolves issue with proxy-redirect nginx configuration

Resolves an issue where the proxy-redirect annotations were not generating the
correct configuration possibly because of user error. This is done by only
setting the proxy_redirect if both proxy-redirect-from and proxy-redirect-to
have valid values. Also adds the e2e tests.

Fixes #2074

test/e2e/framework/framework.go

@@ -262,7 +262,7 @@ func (f *Framework) matchNginxConditions(name string, matcher func(cfg string) b
 				glog.Infof("nginx.conf:\n%v", o)
 			}
 
-			if matcher(o) {
+			if matcher(strings.Join(strings.Fields(o), " ")) {
 				match = true
 			}
 		})