Support drop column in spark also like in postgresql

spark-sql> drop database if exists hivemetastoretest cascade;
Time taken: 1.067 seconds
spark-sql> create database hivemetastoretest;
Time taken: 0.326 seconds
spark-sql> use hivemetastoretest;
Time taken: 0.053 seconds
spark-sql> create table jobit4 using parquet as select 2.5;
Time taken: 5.058 seconds
spark-sql> alter table jobit4 add columns(name string);
Time taken: 1.194 seconds
spark-sql> alter table jobit4 drop columns(name);
Error in query:
mismatched input 'columns' expecting \{'PARTITION', 'IF'}(line 1, pos 25)

== SQL ==
 alter table jobit4 drop columns(name)
-------------------------^^^

spark-sql> alter table jobit4 drop columns name;
Error in query:
mismatched input 'columns' expecting \{'PARTITION', 'IF'}(line 1, pos 25)

== SQL ==
 alter table jobit4 drop columns name
-------------------------^^^

spark-sql> [