Add loan and credit card views (#1268)

* Add loan and credit card views

* Lint fix

* Clean up overview card markup

* Lint fix

* Test fix

app/controllers/loans_controller.rb

@@ -0,0 +1,39 @@
+class LoansController < ApplicationController
+  before_action :set_account, only: :update
+
+  def create
+    account = Current.family
+                     .accounts
+                     .create_with_optional_start_balance! \
+                       attributes: account_params.except(:start_date, :start_balance),
+                       start_date: account_params[:start_date],
+                       start_balance: account_params[:start_balance]
+
+    account.sync_later
+    redirect_to account, notice: t(".success")
+  end
+
+  def update
+    @account.update_with_sync!(account_params)
+    redirect_to @account, notice: t(".success")
+  end
+
+  private
+
+    def set_account
+      @account = Current.family.accounts.find(params[:id])
+    end
+
+    def account_params
+      params.require(:account)
+        .permit(
+          :name, :balance, :start_date, :start_balance, :currency, :accountable_type,
+          accountable_attributes: [
+            :id,
+            :rate_type,
+            :interest_rate,
+            :term_months
+          ]
+        )
+    end
+end