Refactored remove_column

[ebeigarts]

ActiveRecord::Table#remove should use *column_names instead of column_names.

So, I have removed unnecessary flatten for column_names that also caused issues here.

[jonleighton]

Unsure about this. I agree with the principle but there might be apps in the wild that are passing an array to remove_column. cc @tenderlove

[ebeigarts]

At least it isn't documented anywhere that we can pass nested Arrays in column_names here.

[drogus]

I would add deprecation warning and merge it after next release

[carlosantoniodasilva]

This should be ok for master now?

[carlosantoniodasilva]

@ebeigarts hey, could you bring this up-to-date with master, so we can review it and continue the discussion? Thanks.

@jonleighton can we go ahead to merge this in master?

[jonleighton]

We can merge this if a deprecation is added.

[drogus]

I've rebased that commit and added deprecation warning here: drogus@d7e60b6, @jonleighton does it look good, should I push those?

[jonleighton]

@drogus seems fine

[drogus]

I've deprecated this behavior here: 02ca915