Proper error message for undefined where options (#1022)
Proper error message for undefined where options (#1022)

When user provides a knex select statement with an undefined options in where clause it is not properly handled an give an ambiguous error message telling `Unhandled rejection TypeError: Cannot read property 'toString' of undefined.` This PR will helpful to users at it will tell them the exact problem.
brianc/node-postgres,cricri/node-postgres,brianc/node-postgres