added user management system

invsystem/user_manager/forms.py

@@ -0,0 +1,11 @@
+from django.contrib.auth.forms import UserCreationForm
+from django.forms import CharField
+from django.contrib.auth.models import User
+
+
+class SignUpForm(UserCreationForm):
+    username = CharField(required=True)
+
+    class Meta:
+        model = User
+        fields = ('username', 'first_name', 'last_name', 'email', 'password1', 'password2', )