code: function getEmberImportAliasName(importDeclaration) {
    if (!importDeclaration.source) return null;
    if (importDeclaration.source.value !== 'ember') return null;
    return importDeclaration.specifiers[0].local.name;
  }
docs: Get alias name of default ember import.
  
  @param  {ImportDeclaration} importDeclaration node to parse
  @return {String}            import name