Fix last contribution date

Author: jc00ke

contributions.md

@@ -9,7 +9,7 @@ A log for contributions and some expenses.
 
 | Date       | Amount Charged | Amount Reimbursed | Balance   | Name                                                      |
 | :--------- | :------------- | :---------------- | :-------- | :-------------------------------------------------------- |
-| 2019/09/07 |                | $98.94            | $0.00     | [Sidekiq](https://sidekiq.org/)                           |
+| 2020/09/07 |                | $98.94            | $0.00     | [Sidekiq](https://sidekiq.org/)                           |
 | 2020/08/23 | $98.94         |                   | -$98.94   | Meetup
 | 2020/07/25 |                | $34.00            | $0.00     | [Relative Path](https://relativepath.io/) c/o Jesse Cooke |
 | 2020/07/25 | $34.00         |                   | -$34.00   | Gandi DNS renewals                                        |