Hotfix body parser for batch endpoint

• up the limit on bodyParser applied on the batch endpoint

Entity too large error

• Explicitly handle too large kraken notification payloads
• Adds devMode utility
• Turn on flow in index.js files

Error handling & documentation

• this release brings bigger changes to error handling:
  • it cleans up a little middleware stack including smart-notifier errors
  • it introduces two types of errors - unhandled error which is handled the same as till now, and transient error which won't be pushed to sentry, but only instrumented in datadog
  • it deprecates dedicated smartNotifierErrorMiddleware
  • smartNotifierHandler in case of error behaves like notifHandler and pass the error down the middleware stack
• added timeout option to Hull.Connector constructor to control the timeout value
• upgrades raven library
• add support for batch handlers for accounts
• adds users_segments and accounts_segments to Context Object
• deprecation Renamed userHandlerOptions to options in notifyHandler
• flow types fixes

0.11.0-beta.3

• fix the requestExtract handler - allow passing path param
• fix the .asUser() and .asAccount() to return traits and track
• adds .asUser().account() method