Use a relative path for the test image
Use a relative path for the test image

It's part of the issue #20 (weird path on Windows). Django File class used
a full file path which resulted in path like C:\Example\pinry\static\C:\... which
is obviously invalid.

QLGu/pinry,lapo-luchini/pinry,pinry/pinry,supervacuo/pinry,rafirosenberg/pinry,lapo-luchini/pinry,Stackato-Apps/pinry,wangjun/pinry,MSylvia/pinry,QLGu/pinry,lapo-luchini/pinry,wangjun/pinry,supervacuo/pinry,MSylvia/pinry,pinry/pinry,pinry/pinry,lapo-luchini/pinry,pinry/pinry,Stackato-Apps/pinry,wangjun/pinry,rafirosenberg/pinry,Stackato-Apps/pinry,MSylvia/pinry,QLGu/pinry,supervacuo/pinry