stringsync:  add to db schema
stringsync:  add to db schema

tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,DrXyzzy/smc,tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,sagemathinc/smc