Merge pull request #340 from vaibhavcisin274/vaibhav

Vaibhav
set the clientside validation
Merge branch 'master' of github.com:vaibhavcisin274/invoice-project into manish
add link of upgrade account
flash message on sign in page
conflicts remove in /sessions/new.html.haml
Merge pull request #341 from vaibhavcisin274/prachi

Prachi
Merge pull request #342 from vaibhavcisin274/manish

Manish
add validation
Merge branch 'master' of github.com:vaibhavcisin274/invoice-project into vaibhav