chore(deps): update dependency vscode-languageserver to v5 (#519)

Author: renovate[bot]

package-lock.json

@@ -60,7 +60,7 @@
     "string-similarity": "^1.1.0",
     "typescript": "~3.0.3",
     "vscode-jsonrpc": "^3.3.1",
-    "vscode-languageserver": "^4.2.1",
+    "vscode-languageserver": "^5.0.0",
     "vscode-languageserver-types": "^3.0.3"
   },
   "devDependencies": {