fix(sol-compiler, sol-resolver): Bug where sol-resolver tried to read a directory (#961)

fix(sol-compiler, sol-resolver): Fix bug where sol-resolver tried to read a directory

packages/sol-compiler/package.json

@@ -92,6 +92,7 @@
         "require-from-string": "^2.0.1",
         "semver": "5.5.0",
         "solc": "^0.4.23",
+        "source-map-support": "^0.5.0",
         "web3-eth-abi": "^1.0.0-beta.24",
         "yargs": "^10.0.3"
     },

packages/sol-compiler/src/cli.ts

@@ -3,6 +3,7 @@
 
 import { logUtils } from '@0xproject/utils';
 import * as _ from 'lodash';
+import 'source-map-support/register';
 import * as yargs from 'yargs';
 
 import { Compiler } from './compiler';