Fix tests to use regexp.QuoteMeta instead of \Q ... \E

[dolmen]

For maximum safety it is better to use regexp.QuoteMeta instead of wrapping a string with \Q and \E (think about the case where the string ends with \).

[jpgoldberg]

Thank you for this and for your other Pull Requests. They are very much appreciated and will be reviewed. I am just slow.

[dolmen]

@jpgoldberg This a 4 lines patch.

[dolmen]

@jpgoldberg ping

[dolmen]

Almost one year later and review still didn't happen.