fix clock in test to use reverse instead of hard-coded url
fix clock in test to use reverse instead of hard-coded url

--HG--
branch : feature/testsuite

arbitrahj/django-timepiece,dannybrowne86/django-timepiece,caktus/django-timepiece,BocuStudio/django-timepiece,dannybrowne86/django-timepiece,josesanch/django-timepiece,gaga3966/django-timepiece,gaga3966/django-timepiece,dannybrowne86/django-timepiece,arbitrahj/django-timepiece,caktus/django-timepiece,josesanch/django-timepiece,gaga3966/django-timepiece,caktus/django-timepiece,arbitrahj/django-timepiece,BocuStudio/django-timepiece,josesanch/django-timepiece,BocuStudio/django-timepiece