Set Issue labels by inputs & add unit test (#12)

* Set Issue labels by inputs

* Add unit test

__tests__/audit.test.ts

@@ -0,0 +1,15 @@
+import {Audit} from '../src/audit'
+
+const audit = new Audit()
+
+describe('npm audit', () => {
+  test('finds vulnerabilities', () => {
+    audit.status = 1
+    expect(audit.foundVulnerability()).toBeTruthy()
+  })
+
+  test('does not find vulnerabilities', () => {
+    audit.status = 0
+    expect(audit.foundVulnerability()).toBeFalsy()
+  })
+})