Removed deprecated getters from bem-entity-name package

[shkarupa-alex]

When running npm test there is deprecation warning in output:

Wed, 28 Jun 2017 11:43:06 GMT @bem/entity-name deprecated modName is kept just for compatibility and can be dropped in the future. Use mod.name instead in BemEntityName { block: 'block' } at at node_modules/@bem/entity-name/lib/entity-name.js:110:9

This patch removes it.

[qfox]

It's a long story, but it's incorrect, we can't drop support of old format in minor ({block, modName, modVal}).

Need something like this:

-    const modName = (typeof modObj === 'string' ? modObj : modObj && modObj.name) || entity.modName;
+    const modName = (typeof modObj === 'string' ? modObj : modObj && modObj.name) ||
+         entity.hasOwnProperty('modName') && entity.modName;

     if (modName) {
         const hasModVal = modObj && modObj.hasOwnProperty('val') || entity.hasOwnProperty('modVal');
-        const modVal = modObj && modObj.val || entity.modVal;
+        const modVal = modObj && modObj.val || entity.hasOwnProperty('modVal') && entity.modVal;

[shkarupa-alex]

Pull request updated to restore backward compatibility