chore(deps): update dependency @types/source-map-support to v0.5.6

Author: renovate[bot]

package.json

@@ -43,7 +43,7 @@
     "@types/lodash": "4.14.178",
     "@types/mocha": "2.2.48",
     "@types/node": "9.6.61",
-    "@types/source-map-support": "0.5.4",
+    "@types/source-map-support": "0.5.6",
     "assert": "1.5.0",
     "commitizen": "2.10.1",
     "cz-conventional-changelog": "2.1.0",