b-table sticky-columns don't work properly unless both `responsive` & `sticky-header` props are set

[dflock]

Describe the bug

b-table sticky-columns don't work properly unless both responsive & sticky-header props are set

Steps to reproduce the bug

Here's a codepen that shows this happening: https://codepen.io/duncanlock/pen/gOOzJXO

Expected behavior

The docs say that either will work, but both seem to be required:

Sticky columns

Columns can be made sticky, where they stick to the left of the table when the table has a horizontal scrollbar. To make a column a sticky column, set the stickyColumn prop in the field's header definition. Sticky columns will only work when the table has either the sticky-header prop set and/or the responsive prop is set.

Versions

Libraries:

• BootstrapVue: 2.0.4
• Bootstrap: 4.3.1
• Vue: 2.6.10

Environment:

• Device: PC
• OS: Ubuntu Linux 16.04.6 LTS x86_64
• Browser: Chrome
• Version: 75

Demo link

https://codepen.io/duncanlock/pen/gOOzJXO

[tmorehouse]

It appears that the classes are not being applied to the tbody sticky column cells.

There might have been a regression since this feature was introduced.

[tmorehouse]

BootstrapVue v2.1.0 has been released, which has a fix for this issue.