Member services fails under load with "database is locked" error

[smithbk]

Description

The following error occurs when running load against memberservices
ERROR: 2016/06/07 22:27:53 eca.go:252: database is locked

I'm not sure if this is it, but see http://stackoverflow.com/questions/32479071/sqlite3-error-database-is-locked-in-golang which was fixed by closing all rows. Perhaps the same?

Describe How to Reproduce

From inside vagrant:
   start membersrvc
   start peer
   cd fabric/sdk/node/bin
   node main.js test.json 

[andresgaragiola]

@srderson can you assign me this issue?