feat: Add Twelve Data provider for exchange rates and securities (#2)

* feat: Add Twelve Data provider for exchange rates and securities

* test: fix hosting controller test, linting

* fix: add countries gem to handle country codes in Twelve Data provider

* fix: allow security search combobox to have no logo

* refactor: update Twelve Data provider use time series endpoint

* fix: set twelve data as default provider

test/models/account/market_data_importer_test.rb

@@ -18,7 +18,7 @@ class Account::MarketDataImporterTest < ActiveSupport::TestCase
     @provider = mock("provider")
     Provider::Registry.any_instance
                       .stubs(:get_provider)
-                      .with(:synth)
+                      .with(:twelve_data)
                       .returns(@provider)
   end
 

test/models/market_data_importer_test.rb

@@ -17,7 +17,7 @@ class MarketDataImporterTest < ActiveSupport::TestCase
     @provider = mock("provider")
     Provider::Registry.any_instance
                       .stubs(:get_provider)
-                      .with(:synth)
+                      .with(:twelve_data)
                       .returns(@provider)
   end