[Bug 1324212] - update Slovak holiday calendar
[Bug 1324212] - update Slovak holiday calendar

[Bug 1324212] - Update Slovak holiday calendar until 2020
mozilla/bedrock,alexgibson/bedrock,schalkneethling/bedrock,CSCI-462-01-2017/bedrock,mkmelin/bedrock,gerv/bedrock,hoosteeno/bedrock,mozilla/bedrock,glogiotatidis/bedrock,hoosteeno/bedrock,flodolo/bedrock,gerv/bedrock,kyoshino/bedrock,sylvestre/bedrock,CSCI-462-01-2017/bedrock,mkmelin/bedrock,MichaelKohler/bedrock,ericawright/bedrock,kyoshino/bedrock,alexgibson/bedrock,gerv/bedrock,MichaelKohler/bedrock,TheoChevalier/bedrock,TheoChevalier/bedrock,pascalchevrel/bedrock,ericawright/bedrock,alexgibson/bedrock,ericawright/bedrock,kyoshino/bedrock,TheoChevalier/bedrock,sgarrity/bedrock,mozilla/bedrock,mkmelin/bedrock,alexgibson/bedrock,Sancus/bedrock,ericawright/bedrock,craigcook/bedrock,sgarrity/bedrock,flodolo/bedrock,schalkneethling/bedrock,kyoshino/bedrock,MichaelKohler/bedrock,craigcook/bedrock,craigcook/bedrock,flodolo/bedrock,sylvestre/bedrock,schalkneethling/bedrock,Sancus/bedrock,craigcook/bedrock,hoosteeno/bedrock,sylvestre/bedrock,MichaelKohler/bedrock,Sancus/bedrock,CSCI-462-01-2017/bedrock,glogiotatidis/bedrock,sylvestre/bedrock,pascalchevrel/bedrock,pascalchevrel/bedrock,gerv/bedrock,CSCI-462-01-2017/bedrock,sgarrity/bedrock,flodolo/bedrock,Sancus/bedrock,mozilla/bedrock,mkmelin/bedrock,glogiotatidis/bedrock,sgarrity/bedrock,schalkneethling/bedrock,hoosteeno/bedrock,TheoChevalier/bedrock,glogiotatidis/bedrock,pascalchevrel/bedrock