Add statistic graph with number of tests made

[rebelthor]

It would be nice to add a graph showing the number of tests that are being done. The partial information can be found below, including source:

1 aprilie 26609
31 martie 24654
30 martie 23103
29 martie ?
28 martie 19663
27 martie 17453
26 martie 15997
25 martie 14446
24 martie 12624
23 martie 11223
22 martie ?
21 martie 8915
20 martie 8284
19 martie 4973

Source: https://www.biziday.ro/215-noi-cazuri-de-coronavirus-confirmate-in-ultimele-24-de-ore-numarul-total-a-urcat-la-2-460-dintre-care-85-au-decedat-iar-34-sunt-in-stare-grava-s-au-vindecat-si-au-fost-eternate-252-de-persoan/

I'm more than willing to do a MR, but it would be helpful if I can get some pointers what I need to modify to get the new graph, and how I can add the data.