FEATURE: start tracking information about migrations that run

This commit adds a new tracking table that lets us know

- When a migration ran
- What version Discourse was at
- How long it took
- What version Rails was at

The built in tracking in Rails is very limited, does not track this info

spec/components/freedom_patches/schema_migration_details_spec.rb

@@ -0,0 +1,32 @@
+require 'rails_helper'
+require_dependency "freedom_patches/schema_migration_details"
+
+describe FreedomPatches::SchemaMigrationDetails do
+
+  # we usually don't really need this model so lets not clutter up with it
+  class SchemaMigrationDetail < ActiveRecord::Base
+  end
+
+  class TestMigration < ActiveRecord::Migration
+    def up
+      sleep 0.001
+    end
+  end
+
+  it "logs information on migration" do
+    migration = TestMigration.new("awesome_migration","20160225050318")
+
+    ActiveRecord::Base.connection_pool.with_connection do |conn|
+      migration.exec_migration(conn, :up)
+    end
+
+    info = SchemaMigrationDetail.find_by(version: "20160225050318")
+
+    expect(info.duration).to be > 0
+    expect(info.git_version).to eq Discourse.git_version
+    expect(info.direction).to eq "up"
+    expect(info.rails_version).to eq Rails.version
+    expect(info.filename).to eq migration.filename
+    expect(info.name).to eq "awesome_migration"
+  end
+end