docs: add libsasl as system requirement on linux (#1257)
docs: add libsasl as system requirement on linux (#1257)

* docs: add libsasl as system requirement on linux

* docs: add openldap as system dependencies on linux too

Fix #1256

timifasubaa/incubator-superset,jeromecn/caravel_viz_full,robert-digit/superset,apache/incubator-superset,BRD-CD/superset,asdf2014/superset,jeromecn/caravel_viz_full,dmigo/incubator-superset,BRD-CD/superset,robert-digit/superset,airbnb/superset,apache/incubator-superset,massgov/incubator-superset,timifasubaa/incubator-superset,FrederichCheng/incubator-superset,robert-digit/superset,apache/incubator-superset,BRD-CD/superset,jeromecn/caravel_viz_full,airbnb/caravel,robert-digit/superset,airbnb/caravel,airbnb/superset,FrederichCheng/incubator-superset,airbnb/caravel,dmigo/incubator-superset,jeromecn/caravel_viz_full,zhouyao1994/incubator-superset,timifasubaa/incubator-superset,nekia/incubator-superset-dev,airbnb/caravel,SingTel-DataCo/incubator-superset,ArijanaBrlek/superset,mistercrunch/panoramix,mistercrunch/panoramix,FrederichCheng/incubator-superset,airbnb/superset,mistercrunch/panoramix,SingTel-DataCo/incubator-superset,alanmcruickshank/superset-dev,ArijanaBrlek/superset,nekia/incubator-superset-dev,SingTel-DataCo/incubator-superset,zhouyao1994/incubator-superset,nekia/incubator-superset-dev,alanmcruickshank/superset-dev,asdf2014/superset,airbnb/superset,apache/incubator-superset,massgov/incubator-superset,timifasubaa/incubator-superset,zhouyao1994/incubator-superset,FrederichCheng/incubator-superset,ArijanaBrlek/superset,asdf2014/superset,zhouyao1994/incubator-superset,mistercrunch/panoramix,SingTel-DataCo/incubator-superset,massgov/incubator-superset,dmigo/incubator-superset,zhouyao1994/incubator-superset,ArijanaBrlek/superset,alanmcruickshank/superset-dev,apache/incubator-superset,nekia/incubator-superset-dev,massgov/incubator-superset,dmigo/incubator-superset,asdf2014/superset,BRD-CD/superset,alanmcruickshank/superset-dev