Upgrade to webignition/url ~2 (#10)

Author: webignition

composer.json

@@ -32,7 +32,7 @@
     "require": {
         "php": ">=5.6.0",
         "guzzlehttp/guzzle":"~6",
-        "webignition/url":">=0.1,<2.0",
+        "webignition/url":"~2",
         "webignition/web-resource-retriever":">=0.7,<1",
         "webignition/absolute-url-deriver":">=1.3.3,<2.0",
         "webignition/robots-txt-file":">=2.0,<3"