Fix/bs config schema allows string diagnostic codes

[markwpearce]

Allows setting the bsconfig to have string types for the codes array of diagnostic filters:

bsLint has diagnostic codes like "LINT2001"

e.g.

{
  "diagnosticFilters": [
   {
      src: "./someDir/**",
     codes: ["LINT3011"]
   }
 ]
}

[TwitchBronBron]

Nice. thanks!