Restore 0.26.1 in CHANGELOG.md
Restore 0.26.1 in CHANGELOG.md

...as that release was remove by the release script when
releasing 0.27.0

Change-Id: If0b8e9c07c48b4aed40421cb99aab0ac746544b3

dslomov/bazel-windows,aehlig/bazel,ulfjack/bazel,meteorcloudy/bazel,cushon/bazel,davidzchen/bazel,dslomov/bazel-windows,bazelbuild/bazel,bazelbuild/bazel,bazelbuild/bazel,ulfjack/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,werkt/bazel,cushon/bazel,aehlig/bazel,meteorcloudy/bazel,meteorcloudy/bazel,meteorcloudy/bazel,davidzchen/bazel,ulfjack/bazel,dslomov/bazel-windows,dslomov/bazel,davidzchen/bazel,akira-baruah/bazel,dslomov/bazel,akira-baruah/bazel,katre/bazel,werkt/bazel,akira-baruah/bazel,cushon/bazel,safarmer/bazel,twitter-forks/bazel,davidzchen/bazel,dslomov/bazel-windows,aehlig/bazel,dslomov/bazel-windows,twitter-forks/bazel,ulfjack/bazel,werkt/bazel,twitter-forks/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,ButterflyNetwork/bazel,cushon/bazel,bazelbuild/bazel,werkt/bazel,dslomov/bazel,cushon/bazel,dslomov/bazel-windows,meteorcloudy/bazel,safarmer/bazel,dslomov/bazel,davidzchen/bazel,werkt/bazel,twitter-forks/bazel,safarmer/bazel,perezd/bazel,davidzchen/bazel,katre/bazel,ButterflyNetwork/bazel,safarmer/bazel,ulfjack/bazel,safarmer/bazel,dslomov/bazel,perezd/bazel,perezd/bazel,ulfjack/bazel,aehlig/bazel,akira-baruah/bazel,twitter-forks/bazel,meteorcloudy/bazel,perezd/bazel,katre/bazel,bazelbuild/bazel,perezd/bazel,safarmer/bazel,ulfjack/bazel,davidzchen/bazel,perezd/bazel,aehlig/bazel,akira-baruah/bazel,cushon/bazel,dslomov/bazel,ButterflyNetwork/bazel,akira-baruah/bazel,dslomov/bazel,katre/bazel,katre/bazel,perezd/bazel,katre/bazel,aehlig/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,bazelbuild/bazel,werkt/bazel,aehlig/bazel