Use a bash associative array to speedup task tests

The task plugin tests used to reparse the full output for each test case
in order to extract the specific output a test case needed. Now parse
all the output up front and store each test case's output in an
associative array indexed by the test name. This makes running the tests
faster, 2.5 mins on my machine, down from 3.5 mins. The remaining test
time is mostly test and docker setup now.

Change-Id: I7fc01b4c53d6c42f33c0577a0de8dac966602721
1 file changed