build-unit-test-docker: Update CLI11 1.7.1 -> 1.8.0

meta-oe is using CLI11 1.8.0 now and it introduces some useful APIs like
require_option().

Signed-off-by: Lei YU <mine260309@gmail.com>
Change-Id: Id272c4e440c0a31097d3951794dc63b921dc983b
diff --git a/build-unit-test-docker.sh b/build-unit-test-docker.sh
index 0fc3537..0e45f95 100755
--- a/build-unit-test-docker.sh
+++ b/build-unit-test-docker.sh
@@ -92,7 +92,7 @@
 declare -A PKG_REV=(
   [boost]=1.69.0
   [cereal]=v1.2.2
-  [CLI11]=v1.7.1
+  [CLI11]=v1.8.0
   [fmt]=5.3.0
   # Snapshot from 2019-03-10
   [function2]=e3695b4b4fa3c672e25c6462d7900f8d2417a417