Relax rule: allow TypeScript Triple-Slash Directives

Documented here:
http://www.typescriptlang.org/docs/handbook/triple-slash-directives.html

Fixes: standard/standard#660

eslintrc.json

@@ -151,7 +151,7 @@
     "space-infix-ops": "error",
     "space-unary-ops": ["error", { "words": true, "nonwords": false }],
     "spaced-comment": ["error", "always", {
-      "line": { "markers": ["*package", "!", ","] },
+      "line": { "markers": ["*package", "!", "/", ","] },
       "block": { "balanced": true, "markers": ["*package", "!", ","], "exceptions": ["*"] }
     }],
     "template-curly-spacing": ["error", "never"],