Fix varchar column sizes

[kevinwatson]

We're seeing varchar(80) field sizes in Vertica for fields defined as either string or text. Calling the parent method should fix this issue. We should also ignore the limits set in a migration for integer types.

[kevinwatson]

Sample migration:

class CreateMyTable < ActiveRecord::Migration
  def change
    create_table :my_table, :id => :bigserial do |t|
      t.text :text
      t.string :string
      t.integer :integer
      t.integer :bigserial, limit: 8
      t.float :float
      t.decimal :decimal
      t.datetime :datetime
      t.timestamp :timestamp
      t.time :time
      t.date :date
      t.binary :bytea
      t.boolean :boolean
      t.bigint :bigint
  end
end

Before (note the missing limits on the varchar fields):

CREATE TABLE my_table (id integer, text varchar, string varchar, integer integer, bigserial integer, float float, decimal decimal, datetime datetime, timestamp datetime, time time, date date, bytea bytea, boolean boolean, bigint bigint)

After:

CREATE TABLE my_table (id integer, text varchar(15000), string varchar(255), integer integer, bigserial integer, float float, decimal decimal, datetime datetime, timestamp datetime, time time, date date, bytea bytea, boolean boolean, bigint bigint)

Edit: Added the bigint type and renamed some of the columns

[kevinwatson]

Passing CircleCI tests (under my own account)

[kevinwatson]

I believe this PR is ready for review, @film42 and @mrdeadsake

[mrdeadsake]

Maybe make a pre-release version to put out so we can test it?

Otherwise it looks like it's working