ISSUE lergo 7

Adding create question backend support
Issue Lergo-12 
CRUD operation for lesson
Lergo-6

added two API's 
isValidEmail()
isValidUserName() in UserManager.js to validate username and email

Validation Criteria : 
userName : should be more that 2 char and should contain only alpha
numeric and underscore 
email : should match pattern
abc@pqr.com or abc@pqr.co.in
Merge branch 'lergo-6' of https://github.com/lergo/lergo-ri