So far you have been working alone on designing and crafting the tests. The same process will get complicated when many persons are collaborating on the same file instance, or even worse when creating updated instances of that file. Problems such as overwriting each other's versions or losing track of the correct order of the file versions may arise—not to mention other risks such as completely losing the accomplished work following the unexpected event of a machine failure.
Source control systems are created to resolve the aforementioned conflicts by offering a centralized monitored repository where all files are backed up. Each change on these files is audited, starting from check out until check in, where at that point, the discrepancies between the local and the server versions are resolved by choosing which change to overwrite with what. Alternatively, some source control systems give you the option to forbid operations on a file from the beginning unless that file is not...