Update version to 19.1.0-rc1

Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
11 jobs for 19.1 in 8 minutes and 45 seconds (queued for 1 second)
Status Job ID Name Coverage
  Containers Build
passed #286893
debian

00:00:20

 
  Build+Test
passed #286895
meson-clang

00:05:11

passed #286898
meson-clover-llvm

00:03:00

passed #286899
meson-clover-llvm39

00:02:07

passed #286897
meson-main

00:04:53

passed #286894
meson-swr-glvnd

00:04:25

passed #286896
meson-vulkan

00:02:59

passed #286901
scons-llvm

00:05:42

passed #286900
scons-nollvm

00:05:22

passed #286902
scons-swr

00:03:28

passed #286903
scons-win64

00:08:24