Our implementation now expects draft 15.

Change-Id: I261a090763951110a6c9f03acfda4ae23cc14cfc
Reviewed-on: https://boringssl-review.googlesource.com/11502
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>

We've switched to the version extension, so refresh the corpus.

Change-Id: Ic50f58bd83d62dccae26063c9ea2d4a2c799da1f
Reviewed-on: https://boringssl-review.googlesource.com/11326
Reviewed-by: Adam Langley <agl@google.com>