tests: Move stream creation out of setup and into test functions
tests: Move stream creation out of setup and into test functions

Resetting the stream (seeking back to the beginning and clearing pending
operations) was too fragile, and resulted in spurious test failures.

Pecisk/libgdata,Pecisk/libgdata,pwithnall/libgdata,Distrotech/libgdata,pwithnall/libgdata,Pecisk/libgdata-gtasks,Pecisk/libgdata-gtasks,Distrotech/libgdata,Pecisk/libgdata-gtasks,Distrotech/libgdata,GNOME/libgdata,Pecisk/libgdata