Add test infrastructure

.ava.json

@@ -0,0 +1,3 @@
+{
+    "verbose": true
+}

ava.config.js

@@ -0,0 +1,6 @@
+import fs from 'fs'
+
+const configJson = fs.readFileSync('.ava.json')
+const config = JSON.parse(configJson)
+
+export default config

package.json

@@ -20,15 +20,20 @@
         "@rgrove/parse-xml": "^1.1.1"
     },
     "devDependencies": {
+        "ava": "^1.0.0-rc.2",
         "cross-env": "^5.2.0",
         "jsdoc": "^3.5.5",
         "npm-run-all": "^4.1.5",
+        "sinon": "^7.1.1",
         "snazzy": "^8.0.0",
         "standard": "^12.0.1"
     },
     "scripts": {
         "lint-js": "standard",
         "lint": "npm-run-all lint-js",
-        "doc": "jsdoc -c .jsdoc.json --pedantic"
+        "doc": "jsdoc -c .jsdoc.json --pedantic",
+        "test-unit": "cross-env NODE_PATH=src:test ava test/unit",
+        "test": "npm-run-all test-unit",
+        "test-hoc": "cross-env NODE_PATH=src:test ava"
     }
 }