thead class cannot be overridden in bootstrap 4

[stanorama]

django 2.2.2
django-tables2 2.0.6
Firefox 67.0.1 64-bit
Chrome 74.0.3729.169 64-bit

Passing the class attribute of thead does not work when using the bootstrap 4 template.
This is caused by the inclusion of the default class="thead-default" in the template.
Any other attribute aside from class is being passed correctly.

bootstrap.html

<thead {{ table.attrs.thead.as_html }}>

bootstrap4.html

<thead class="thead-default" {{ table.attrs.thead.as_html }}>

Setting attrs in table meta:

class Meta:
attrs = {'class': 'table table-hover', 'thead':{'class': 'thead-light', 'id':'OK!'}}

From Chrome Inspector showing class has stayed unchanged

I have seen no formatting difference by removing the hard coded class in the template.
tbody and tfoot do not have a hard coded class.

[jieter]

@stanorama thanks for the report.

The table tag shows the proper way to have a default value and overridable class attribute:

django-tables2/django_tables2/templates/django_tables2/bootstrap4.html

Line 6 in dbbd44e

<table {% render_attrs table.attrs class="table" %}>

Are you willing to open a PR fixing this issue?