Changelog update for v1.0.21. (#334)
Changelog update for v1.0.21. (#334)

* Changelog update for v1.0.21.

* Fix spurious blank line.

google/certificate-transparency-go,google/certificate-transparency-go,daviddrysdale/certificate-transparency-go,RJPercival/certificate-transparency-go,daviddrysdale/certificate-transparency-go,daviddrysdale/certificate-transparency-go,RJPercival/certificate-transparency-go,google/certificate-transparency-go,RJPercival/certificate-transparency-go