Add yarn off-line capability

.yarnrc

+yarn-offline-mirror "./.vendor/npm"
+yarn-offline-mirror-pruning true

package.json

+{
+  "dependencies": {
+    "ejs-compile": "^0.0.1"
+  }
+}

yarn.lock

+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+async@0.1.x:
+  version "0.1.22"
+  resolved "https://registry.yarnpkg.com/async/-/async-0.1.22.tgz#0fc1aaa088a0e3ef0ebe2d8831bab0dcf8845061"
+  integrity sha1-D8GqoIig4+8Ovi2IMbqw3PiEUGE=
+
+commander@*:
+  version "2.19.0"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-2.19.0.tgz#f6198aa84e5b83c46054b94ddedbfed5ee9ff12a"
+  integrity sha512-6tvAOO+D6OENvRAh524Dh9jcfKTYDQAqvqezbCW82xj5X0pSrcpxtvRKHLG0yBY6SD7PSDrJaj+0AiOcKVd1Xg==
+
+ejs-compile@^0.0.1:
+  version "0.0.1"
+  resolved "https://registry.yarnpkg.com/ejs-compile/-/ejs-compile-0.0.1.tgz#9753ded925b64c1a20431603ee6c0f079db13628"
+  integrity sha1-l1Pe2SW2TBogQxYD7mwPB52xNig=
+  dependencies:
+    commander "*"
+    ejs "*"
+    read-dir-files "*"
+
+ejs@*:
+  version "2.6.1"
+  resolved "https://registry.yarnpkg.com/ejs/-/ejs-2.6.1.tgz#498ec0d495655abc6f23cd61868d926464071aa0"
+  integrity sha512-0xy4A/twfrRCnkhfk8ErDi5DqdAsAqeGxht4xkCUrsvhhbQNs7E+4jV0CN7+NKIY0aHE72+XvqtBIXzD31ZbXQ==
+
+errs@0.1.x:
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/errs/-/errs-0.1.1.tgz#d4493dcccf0848ed75ee4e3205f606058841baf2"
+  integrity sha1-1Ek9zM8ISO117k4yBfYGBYhBuvI=
+
+read-dir-files@*:
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/read-dir-files/-/read-dir-files-0.1.1.tgz#d79ecfdf323ac0a4d4ac6e2293387e974ed21782"
+  integrity sha1-157P3zI6wKTUrG4ikzh+l07SF4I=
+  dependencies:
+    async "0.1.x"
+    errs "0.1.x"