test: remove z-index spec

Author: aminya

spec/minimap-main-spec.js

@@ -178,12 +178,10 @@ describe('Minimap package', () => {
 
         it('creates a default config for the plugin', () => {
           expect(minimapPackage.getConfigSchema().plugins.properties.dummy).toBeDefined()
-          expect(minimapPackage.getConfigSchema().plugins.properties.dummyDecorationsZIndex).toBeDefined()
         })
 
         it('sets the corresponding config', () => {
           expect(atom.config.get('minimap.plugins.dummy')).toBeTruthy()
-          expect(atom.config.get('minimap.plugins.dummyDecorationsZIndex')).toEqual(0)
         })
 
         describe('triggering the corresponding plugin command', () => {