[BUG][Javascript] Can not build the generated code Invalid version

Created by: tmkasun

Bug Report Checklist

Have you provided a full/minimal spec to reproduce the issue?
Have you validated the input using an OpenAPI validator (example)?
What's the version of OpenAPI Generator used?
Have you search for related issues/PRs?
What's the actual output vs expected output?
[Optional] Bounty to sponsor the fix (example)

Description

Can't run the

npm run build

command on the generated (Javascript ES6) code since the package.json file contains an invalid version number.

openapi-generator version

4.2.0

OpenAPI declaration file content or url

Swagger definition

Command line used for generation

java -jar openapi-generator-cli.jar generate -i /path/to/definition.yaml -g javascript -o /tmp/sample/

Steps to reproduce

Download the openapi-generator-cli.jar
Try to build a Javascript NodeJS client with the above mention or any other OpenAPI definition file
Check the generated package.json file version
Try to build the generated API client package
It will throw following exception

npm ERR! Invalid version: "v1"

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/tmkasun/.npm/_logs/2019-11-10T14_10_24_564Z-debug.log
The terminal process terminated with exit code: 1

Related issues/PRs

Suggest a fix

need to generate the package.json file with valid semantic versioning string in the version field