feat: add crypto account type to demo data (#555)

* feat: add crypto account type to demo data

* fix: set currency to BTC, revert schema migration change and fix tests

* fix: update dates in time_series tests

test/fixtures/account/cryptos.yml

@@ -0,0 +1,11 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+# This model initially had no columns defined. If you add columns to the
+# model remove the "{}" from the fixture names and add the columns immediately
+# below each fixture, per the syntax in the comments below
+#
+# one: {}
+# column: value
+#
+# two: {}
+# column: value