message: Add vsce to dev dependencies.
diff: "semver": "5.4.1"
  },
  "devDependencies": {
  - "typescript": "^2.5.2",
  - "vscode": "^1.1.5",
  - "mocha": "^3.5.0",
  + "@types/mocha": "^2.2.42",
  "@types/node": "^8.0.26",
  - "@types/mocha": "^2.2.42"
  + "mocha": "^3.5.0",
  + "typescript": "^2.5.2",
  + "vsce": "^1.30.0",
  + "vscode": "^1.1.5"
  },
  "icon": "images/lean_logo.png",
  "license": "Apache-2.0"
  