Changes

Remove from list when updated to contract work page [https://contractwork.vipulnaik.com/worker.php?worker=Sebastian+Sanchez] and [https://github.com/vipulnaik/contractwork/blob/master/contributor-lists/sebastian-sanchez-list.mediawiki].

** Vipul: What I meant with the Reddit subscriber counts was a little different: rather than having a separate row giving the subscriber count for the main reddit, edit the existing rows for the creation of various subreddits, to give the subscriber count as of today (rather than as of June 12, 2017, or whenever the subscriber count was last updated). So can you remove the row for March 19, 2020 and make updates to the rows for individual subreddits?✔

** Vipul: Add Bitcoin Core version 0.19.1 row (released March 9, 2020)✔