Fix the label of the date field in the filter

[sstoyanov7]

Fix bug displaying humanized label, instead of specified label via ->label("Label text")

For example the date filter field in the code below:

• Before the fix was displaying Created at from humanized 'created_at', which is incorrect.
• After the fix is displaying Create date provided via ->label("Create date"), which is correct.

        $filter = Tart::filter($this->request->query())
            ->entries([
                'created_at' => Tart::entry('date', null, function ($collection, $value) {
                    return $collection->where('...');
                })->label('Created date'),
            ]);

[hkdobrev]

@sstoyanov7 Could you also remove the failing hhvm from the build matrix while you're at it? Thanks!

[sstoyanov7]

@hkdobrev sure, removed hhvm as requested.