update license file

5 jobs for v2.6.0 in 33 minutes and 56 seconds (queued for 75 minutes and 1 second)
latest
Status Job ID Name Coverage
  Test
passed #32715
duneci
debian:10 gcc:c++17

00:09:33

passed #32717
duneci
debian:9--clang

00:06:05

passed #32716
duneci
debian:9--gcc

00:06:19

passed #32719
duneci
ubuntu:16.04--clang

00:06:03

passed #32718
duneci
ubuntu:16.04--gcc

00:05:54