Bring str_like to dbplyr

[rjpat]

Currently have str_like() in {stringr}, will add a PR

[rjpat]

Realised some problems. Will review and resubmit

[hadley]

stringr doesn't have a str_like() function?

[rjpat]

Sorry should have been more explicit, str_like() is here, there has not been a release since it was merged.

[hadley]

I clearly totally forgot about str_like(); I'm happy to re-review the PR if you want to re-submit it 😄