Update json_pure dependency to version 1.5.4
Update json_pure dependency to version 1.5.4

openeducation/travis-ci,openeducation/travis-ci,flores/travis-ci,flores/travis-ci,fxposter/travis-ci,flores/travis-ci,openeducation/travis-ci,fxposter/travis-ci,fxposter/travis-ci