feat(previewer): add beforePreview and afterPreview hooks

Status Job ID Name Coverage
  Test
failed #339
build_image

00:00:24

 
Name Stage Failure
failed
build_image Test
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the pagedjs@0.1.34 tests script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! /home/node/.npm/_logs/2019-08-22T15_28_18_392Z-debug.log
npm ERR! Test failed. See above for more details.
ERROR: Job failed: exit status 1