Add 2 new commands:

* populate_billing_email
* non_unique_emails
Signed-off-by: Birin Sanchez <birin.sanchez@puri.sm>

purist/management/commands/non_unique_emails.py

+from django.core.management.base import BaseCommand
+from purist.models import User
+
+
+class Command(BaseCommand):
+    help = 'Shows what recovery emails are used in more than one account.'
+
+    def handle(self, *args, **options):
+        sql_query = 'SELECT id,email,COUNT(email) AS count from purist_user \
+        GROUP BY email HAVING COUNT(email) > 1'
+        query = User.objects.raw(sql_query)
+
+        msg1 = "\nRecovery email '{}' is used {} times by the following users:"
+        msg2 = '   {}'
+        for item in query:
+            print(msg1.format(item.email, item.count))
+            users = User.objects.filter(email=item.email)
+            for user in users:
+                print(msg2.format(user.username))

purist/management/commands/populate_billing_email.py

+from django.core.management.base import BaseCommand
+from purist.models import User
+import time
+
+
+class Command(BaseCommand):
+    help = "Populate billing_email value for users that don't have it set. If \
+            the user has a WooCommerce email this value will be used. \
+            Otherwise the User.get_identity() identity will be used."
+
+    def add_arguments(self, parser):
+        parser.add_argument('--wait',
+                            type=int,
+                            help='Number of seconds to wait between users. \
+                            Default is 0.',
+                            default=0)
+
+    def handle(self, *args, **options):
+        wait_time = options['wait']
+        # Get all users with billing_email = ''
+        usr_empty = User.objects.filter(billing_email='')
+
+        self.stdout.write('Processing users with no billing_email')
+        for user in usr_empty:
+            wc_email = user.get_woocommerce_billing_email()
+            if wc_email is None or wc_email == '':
+                user.billing_email = user.get_identity()
+            else:
+                user.billing_email = wc_email
+            user.save()
+            self.stdout.write(' User {}:'.format(user.username))
+            self.stdout.write('   New billing_email: {}'.format(
+                user.billing_email))
+            time.sleep(wait_time)