Update requirements
Update requirements

Update the requirements to support all versions of Django after 1.3.

barseghyanartur/djorm-ext-pgfulltext,asmedeus/djorm-ext-pgfulltext,pombredanne/djorm-ext-pgfulltext,gsong/djorm-ext-pgfulltext,linuxlewis/djorm-ext-pgfulltext,megahall/djorm-ext-pgfulltext