Scaffold out basic transactions model and UI (#478)

* Transaction scaffold

* Rough in transaction views

* Fix sort order

* Fix mass assignment issue

* Fix test

* Simplify CI workflow

* Don't seed db before test

app/models/account.rb

@@ -3,6 +3,7 @@ class Account < ApplicationRecord
   belongs_to :family
   has_many :balances, class_name: "AccountBalance"
   has_many :valuations
+  has_many :transactions
 
   delegated_type :accountable, types: Accountable::TYPES, dependent: :destroy
 

app/models/family.rb

@@ -1,4 +1,5 @@
 class Family < ApplicationRecord
   has_many :users, dependent: :destroy
   has_many :accounts, dependent: :destroy
+  has_many :transactions, through: :accounts
 end

app/models/transaction.rb

@@ -0,0 +1,3 @@
+class Transaction < ApplicationRecord
+  belongs_to :account
+end