Use "history: false" to create a single copy of each repo
The feature "history: false" added to a test definition saves disk space by removing the .git directory.
However, it would also be nice if the repo could be shared between all tests that use the same repo and branch.
For example, on my WaRP7 board, I want to run 18 tests, all from the same repo. However, I don't have enough disk space because a copy of the repo (minus .git dir) is needed for each test.
Migrated from https://projects.linaro.org/browse/LAVA-1379