Local development server to log on stdout

[arundhaj]

When running chalice local server, this change would enable the app to log in stdout.

The following code that logs in CloudWatch when running on AWS Lambda, will also work during local.

import logging

logger = logging.getLogger()
logger.setLevel(logging.INFO)

@app.route('/')
def index():
    logger.info('Log in stdout when local and in CloudWatch on AWS Lambda')
    return {'hello': 'world'}

[jamesls]

Thanks for the pull request. I made one small change and moved this logic out of module scope and into the local function in chalice.cli. Otherwise looks good.