Add underscore as a dependency to CLI

Patch until ConsenSys-archive/truffle#2256 is released.

Author: spalladino

packages/cli/package-lock.json

@@ -117,6 +117,7 @@
     "solidity-parser-antlr": "^0.4.2",
     "spinnies": "^0.3.0",
     "truffle-config": "1.1.16",
+    "underscore": "^1.9.1",
     "web3": "1.2.0",
     "web3-utils": "1.2.0"
   },