[misc] Upgrade to slf4j 1.7.6
[misc] Upgrade to slf4j 1.7.6

JKereliuk/phenotips,phenotips/phenotips,DeanWay/phenotips,alexhenrie/phenotips,JKereliuk/phenotips,teyden/phenotips,alexhenrie/phenotips,phenotips/phenotips,tmarathe/phenotips,itaiGershtansky/phenotips,danielpgross/phenotips,tmarathe/phenotips,alexhenrie/phenotips,tmarathe/phenotips,DeanWay/phenotips,danielpgross/phenotips,itaiGershtansky/phenotips,itaiGershtansky/phenotips,mjshepherd/phenotips,DeanWay/phenotips,veronikaslc/phenotips,mjshepherd/phenotips,phenotips/phenotips,veronikaslc/phenotips,teyden/phenotips,phenotips/phenotips,teyden/phenotips,phenotips/phenotips,danielpgross/phenotips,mjshepherd/phenotips,teyden/phenotips,JKereliuk/phenotips,veronikaslc/phenotips,teyden/phenotips