chore(package): update text-buffer to version 13.11.6

Closes #50

Author: greenkeeper[bot]

package.json

@@ -18,7 +18,7 @@
     "blue-tape": "^1.0.0",
     "onchange": "^3.2.1",
     "tap-spec": "^4.1.1",
-    "text-buffer": "13.11.3",
+    "text-buffer": "13.11.6",
     "ts-node": "^4.0.0",
     "tslint": "^5.4.3",
     "tslint-config-typings": "^0.3.1",