Bump filp/whoops from 2.2.0 to 2.2.1 (#811)

Bumps [filp/whoops](https://github.com/filp/whoops) from 2.2.0 to 2.2.1.
<details>
<summary>Commits</summary>

- [`e79cd40`](e79cd403fb) Merge pull request [#582](https://github-redirect.dependabot.com/filp/whoops/issues/582) from gharlan/editor-callable-allow-empty
- [`e730eb2`](e730eb22af) editor callback: allow to return empty value
- [`45dad4e`](45dad4e41e) Merge pull request [#578](https://github-redirect.dependabot.com/filp/whoops/issues/578) from GrahamCampbell/patch-1
- [`abcc980`](abcc9806c8) Fixed branch alias
- [`d476ee0`](d476ee0c85) Changelog for 2.2.0
- See full diff in [compare view](https://github.com/filp/whoops/compare/2.2.0...2.2.1)
</details>
<br />

[![Dependabot compatibility score](https://api.dependabot.com/badges/compatibility_score?dependency-name=filp/whoops&package-manager=composer&previous-version=2.2.0&new-version=2.2.1)](https://dependabot.com/compatibility-score.html?dependency-name=filp/whoops&package-manager=composer&previous-version=2.2.0&new-version=2.2.1)

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composer.lock

@@ -3760,16 +3760,16 @@
         },
         {
             "name": "filp/whoops",
-            "version": "2.2.0",
+            "version": "2.2.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/filp/whoops.git",
-                "reference": "181c4502d8f34db7aed7bfe88d4f87875b8e947a"
+                "reference": "e79cd403fb77fc8963a99ecc30e80ddd885b3311"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/filp/whoops/zipball/181c4502d8f34db7aed7bfe88d4f87875b8e947a",
-                "reference": "181c4502d8f34db7aed7bfe88d4f87875b8e947a",
+                "url": "https://api.github.com/repos/filp/whoops/zipball/e79cd403fb77fc8963a99ecc30e80ddd885b3311",
+                "reference": "e79cd403fb77fc8963a99ecc30e80ddd885b3311",
                 "shasum": ""
             },
             "require": {
@@ -3788,7 +3788,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "2.1-dev"
+                    "dev-master": "2.2-dev"
                 }
             },
             "autoload": {
@@ -3817,7 +3817,7 @@
                 "throwable",
                 "whoops"
             ],
-            "time": "2018-03-03T17:56:25+00:00"
+            "time": "2018-06-30T13:14:06+00:00"
         },
         {
             "name": "fzaninotto/faker",