Fix two failing tests
Fix two failing tests

On Linux the resolution of LastWriteTime seems to be a second
instead of the finer resolution on Windows, so we have to wait
an entire second before writing the second file if we want to
compare the timestamps.

sillsdev/LfMerge,sillsdev/LfMerge,ermshiperete/LfMerge,sillsdev/LfMerge,ermshiperete/LfMerge,ermshiperete/LfMerge