Here are their feature tracking charts, showing a nice increase in the HTTPS results found in the top ten Google listings that they each, respectively, track:
RankRanger is showing an increase from August 1st of an average result ranking for HTTPS of 2.93 compared to August 15th of 3.17. Mozcast shows on August 1st, 33.9% of the top results are HTTPS and then on August 14th, 35.6% of those results are HTTPS.
Both these independent tracking tools are showing increases in HTTPS results in the top results at Google.
I did ask Google if they have tweaked the HTTPS ranking boost, but no response as of yet.
Forum discussion at Twitter.
Update: Google's Gary Illyes said no, they did not do an HTTPS update. So maybe some more sites in the top ten converted to HTTPS:
@rustybrick no— Gary Illyes (@methode) August 15, 2016
Update 2: Gary Illyes from Google said the data from these guys seem to be wrong: