branch CI jobs turned off for travis and appveyor, closes #2743 (#2757)
branch CI jobs turned off for travis and appveyor, closes #2743 (#2757)


vlulla/data.table,Rdatatable/data.table,jangorecki/data.table,jangorecki/data.table,Rdatatable/data.table,Rdatatable/data.table,jangorecki/data.table,jangorecki/data.table,vlulla/data.table,Rdatatable/data.table,vlulla/data.table,vlulla/data.table