Drop and rename table/column/indexes/constraints

[marcotas]

• drop table -> drop('table') and dropIfExist('table')
• drop column -> table.dropColumn('column') and table.dropColumns(['column'])
• drop compounds -> table.dropSoftDeletes(), table.dropTimestamps()
• drop index -> table.dropIndex(column: 'name') and table.dropIndex(columns: ['name']) and table.dropIndex(name: 'test_name_index')
• drop unique -> table.dropUnique(column, columns or name)
• drop primary -> table.dropPrimary(name?)
• rename table -> Schema.rename('from', 'to')
• rename column -> table.renameColumn('from', 'to')
• rename index -> table.renameIndex('from', 'to')