TLS 1.0 Connections to Heroku's Platform API to be Disabled on August 31st, 2017
Change effective on 13 July 2017
Connections to Heroku’s Platform API using TLS 1.0 are deprecated. All connections using TLS 1.0 will work until August 31st, at which point TLS 1.0 connections will be disabled. Clients using TLS 1.0 should upgrade to TLS 1.1 or 1.2 to avoid interruptions. This only affects the Platform API and does not affect routing to dynos.