update README
usable even withot ``django-cache-machine``
bump version number
Merge branch 'release/0.4.5'

* release/0.4.5:
  bump version number
  usable even withot ``django-cache-machine``
  update README
Merge tag '0.4.5' into develop

0.4.5

* tag '0.4.5':
  bump version number