Incorporate update for blocks gas_used and gas_limit in initial migration

apps/explorer/priv/repo/migrations/20180117221922_create_blocks.exs

@@ -4,8 +4,8 @@ defmodule Explorer.Repo.Migrations.CreateBlocks do
   def change do
     create table(:blocks, primary_key: false) do
       add(:difficulty, :numeric, precision: 50)
-      add(:gas_limit, :integer, null: false)
-      add(:gas_used, :integer, null: false)
+      add(:gas_limit, :numeric, precision: 100, null: false)
+      add(:gas_used, :numeric, precision: 100, null: false)
       add(:hash, :bytea, null: false, primary_key: true)
       add(:miner_hash, references(:addresses, column: :hash, type: :bytea), null: false)
       add(:nonce, :bytea, null: false)

apps/explorer/priv/repo/migrations/20180831231919_modify_block_gas.exs

@@ -1,10 +0,0 @@
-defmodule Explorer.Repo.Migrations.ModifyBlockGas do
-  use Ecto.Migration
-
-  def change do
-    alter table(:blocks) do
-      modify(:gas_used, :numeric, precision: 100)
-      modify(:gas_limit, :numeric, precision: 100)
-    end
-  end
-end