feat: bump minimum node version to 16 and add tests (#86)

BREAKING CHANGE: Minimum node version is now 16

test/sha.spec.ts

@@ -0,0 +1,11 @@
+import * as path from 'path';
+
+import { sha } from '../src/sha';
+
+describe('sha', () => {
+  it('should correctly hash a file', async () => {
+    expect(await sha(path.resolve(__dirname, 'fixtures', 'tohash'))).toEqual(
+      '12998c017066eb0d2a70b94e6ed3192985855ce390f321bbdb832022888bd251',
+    );
+  });
+});