chore(package): update ava to version 2.0.0

package.json

@@ -3,6 +3,14 @@
   "description": "Automated semver compliant package publishing",
   "version": "0.0.0-development",
   "author": "Stephan Bönnemann <stephan@boennemann.me> (http://boennemann.me)",
+  "ava": {
+    "files": [
+      "test/**/*.test.js"
+    ],
+    "helpers": [
+      "test/helpers/**/*"
+    ]
+  },
   "bin": {
     "semantic-release": "bin/semantic-release.js"
   },
@@ -47,7 +55,7 @@
     "yargs": "^13.1.0"
   },
   "devDependencies": {
-    "ava": "^1.3.1",
+    "ava": "^2.0.0",
     "clear-module": "^3.0.0",
     "codecov": "^3.0.0",
     "commitizen": "^3.0.0",