Remove shortLabel requirement

Author: cmdcolin

src/trackDbFile.test.ts

@@ -33,7 +33,7 @@ describe('TrackDbFile', () => {
     expect(
       () =>
         new TrackDbFile('track dnaseSignal\nbigDataUrl dnaseSignal.bigWig\n'),
-    ).toThrow(/Track .* is missing required key\(s\):/))
+    ).toThrow(/Neither/))
 
   it("throws if each track isn't a parent track and doesn't have bigDataUrl", () =>
     expect(

src/trackDbFile.ts

@@ -24,7 +24,7 @@ export default class TrackDbFile extends RaFile {
     for (const [trackName, track] of this.entries()) {
       const trackKeys = [...track.keys()]
       const missingKeys = [] as string[]
-      const requiredKeys = ['track', 'shortLabel']
+      const requiredKeys = ['track']
       for (const key of requiredKeys) {
         if (!trackKeys.includes(key)) {
           missingKeys.push(key)