Add updateObject function and Script file to run it

[anuragparida]

• Added updateObject() function to ./src/services/cloud-storage/bucket.js which allows the user to replace an existing object in the specified bucket with a new object in the specified path.
• Makes use of the uploadObject() and deleteObject() methods.

• Also Added Script file and corresponding JS file for running the function in CLI. (Takes 3 inputs - path, fileName and bucketName)