Fixture value is quoted by Arel, however scalar values are not quotable. In
this case we want to convert the column value to YAML.
# File activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb, line 489
def with_yaml_fallback(value) # :nodoc:
if value.is_a?(Hash) || value.is_a?(Array)
YAML.dump(value)
else
value
end
end