updated path to strip coverletter script

[lsh-0]

depends on:

• https://github.com/elifesciences/elife-bot-formula/pull/20
• https://github.com/elifesciences/strip-coverletter/pull/7 (merged)

[gnott]

Feel free to merge if the new executable is ready, then this will be deployed in the next elife-bot build.

[lsh-0]

cheers, @gnott - there are some build problems in the formula that I'm looking at right now before I can merge

[lsh-0]

strip-coverletter and elife-bot-formula changes have passed testing and been merged in. merging this one now