Revise paste update forms.py and create admin.py in app accounts

App accounts:

1. In forms.py we add:

class MyHolidayUserChangeForm(auth_forms.UserChangeForm):
    class Meta(auth_forms.UserChangeForm.Meta):
        model = UserModel

2. In admin.py we add:

from django.contrib import admin
from django.contrib.auth import admin as auth_admin

from my_holiday.accounts.forms import MyHolidayUserCreationForm, MyHolidayUserChangeForm

UserModel = get_user_model()

@admin.register(UserModel)
class AppUserAdmin(auth_admin.UserAdmin):
    model = UserModel
    add_form = MyHolidayUserCreationForm
    form = MyHolidayUserChangeForm

list_display = ('pk', 'email', 'is_staff', 'is_superuser')
    search_fields = ('email',)
    ordering = ('pk',)

fieldsets = (
        (None, {'fields': ('email', 'password')}),
        ('Personal info', {'fields': ()}),
        ('Permissions', {'fields': ('is_active', 'is_staff', 'groups', 'user_permissions')}),
        ('Important dates', {'fields': ('last_login',)}),
    )

add_fieldsets = (
        (
            None,
            {
                "classes": ("wide",),
                "fields": ("email", "password1", "password2"),
            },
        ),
    )