Add Account type investment form (#343)

* Add Account type investment form

* Move subtypes to Account::Investment

* Linting

app/models/account/investment.rb

@@ -1,3 +1,15 @@
 class Account::Investment < ApplicationRecord
   include Accountable
+
+  SUBTYPES = [
+    [ "Brokerage", "brokerage" ],
+    [ "Pension", "pension" ],
+    [ "Retirement", "retirement" ],
+    [ "401(k)", "401k" ],
+    [ "529 plan", "529_plan" ],
+    [ "Health Savings Account", "hsa" ],
+    [ "Mutual Fund", "mutual_fund" ],
+    [ "Roth IRA", "roth_ira" ],
+    [ "Roth 401k", "roth_401k" ]
+  ].freeze
 end