typescript: error TS2693: 'Promise' only refers to a type, but is being used as a value here

將ts配置文件中 "target": "es2015"

{
    "compilerOptions": {
        "outDir": "./dist/",
        "sourceMap": false,
        "noImplicitAny": false,
        "module": "commonjs",
        "target": "es2015"
    },
    "include": [
        "src/**/*"
    ],
    "exclude": [
        "node_modules",
        "**/*.spec.ts"
    ]
}