Added some tests

tests/node_modules/tap-spec/bin/cmd.js

@@ -0,0 +1,19 @@
+#!/usr/bin/env node
+
+var tapSpec = require('../');
+var tapSpec = tapSpec();
+
+process.stdin
+  .pipe(tapSpec)
+  .pipe(process.stdout);
+
+process.on('exit', function (status) {
+  
+  if (status === 1) {
+    process.exit(1);
+  }
+  
+  if (tapSpec.failed) {
+    process.exit(1);
+  }
+});