Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1070730
Description of problem:

hammer accepts invalid email addresses when creating users:

for example:

1. hammer user create --auth-source-id 1 --password testing --login user1 --mail "specialchars():;@example.com"
   User created

1. hammer user create --auth-source-id 1 --password testing --login user2 --mail 's p a c e s@example.com'
   User created

1. hammer user create --auth-source-id 1 --password testing --login user3 --mail 'dots..@example.com'
   User created

1. hammer user list
   ID | LOGIN | NAME | EMAIL
   163 | user1 | | specialchars():;@example.com
   165 | user2 | | spaces@example.com
   166 | user3 | | dots..@example.com

and it also accepts empty string as email address:

1. hammer user create --login user4 --mail '' --auth-source-id 1 --password pass
   User created

and does not accept (unusual) valid addresses (see http://en.wikipedia.org/wiki/Email_address#Valid_email_addresses):
e.g.:

1. hammer user create --login user5 --mail '"very.unusual.@.unusual.com"@example.com' --auth-source-id 1 --password pass
   Could not create the user:
   Email address is invalid

Version-Release number of selected component (if applicable):
foreman-postgresql-1.5.0-0.develop.201402250936git8cf1033.el6.noarch
foreman-release-1.5.0-0.develop.201402250936git8cf1033.el6.noarch
dell-pem710-01.rhts.eng.bos.redhat.com-foreman-proxy-1.0-1.noarch
foreman-proxy-1.5.0-0.develop.201402201704gita25e7b9.el6.noarch
dell-pem710-01.rhts.eng.bos.redhat.com-foreman-client-1.0-1.noarch
rubygem-foreman_api-0.1.11-1.el6.noarch
foreman-1.5.0-0.develop.201402250936git8cf1033.el6.noarch
rubygem-hammer_cli_foreman-0.0.18-1.el6.noarch
foreman-selinux-1.5.0-0.develop.201401221845git5f25c33.el6.noarch
rubygem-hammer_cli-0.0.18-1.el6.noarch
rubygem-hammer_cli_katello-0.0.3-1.el6.noarch

How reproducible:
always