Fix Readme - Extra endcall in mock test with Column Seperator = '|'

[Amar-AIcloud]

Hi

While I was working on a mock test I copied the code from readme and made adjustments accordingly to my tables. I found that it has an extra endcall at the end of the code.

  {% call dbt_unit_testing.expect({"input_format": "csv"}) %}
    customer_id | customer_lifetime_value
    1           | 20
  {% endcall %}
{% endcall %}

{% endcall %}

Error:

Compilation Error in test test_web_promotions (tests\unit_tests\.sql)
  Encountered unknown tag 'endcall'.
    line 22
      {% endcall %}