patch 8.1.0841: travis config to get Lua on MacOS is too complicated

Problem:    Travis config to get Lua on MacOS is too complicated.
Solution:   Use an addons entry. (Ozaki Kiichi, closes 3876)
diff --git a/.travis.yml b/.travis.yml
index cf95cd6..277e6fe 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -82,6 +82,10 @@
       - tcl-dev
       - cscope
       - libgtk2.0-dev
+  homebrew:
+    packages:
+      - lua
+    update: true
 
 before_install:
   - rvm reset
@@ -93,7 +97,7 @@
     # building cffi only works with gcc, not with clang
   - if [ "$COVERAGE" = "yes" ]; then CC=gcc pip install --user pyopenssl ndg-httpsclient pyasn1; fi
     # Lua is not installed on Travis OSX
-  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then export HOMEBREW_NO_AUTO_UPDATE=1; brew update; brew install lua; export LUA_PREFIX=/usr/local; fi
+  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then export LUA_PREFIX=/usr/local; fi
     # Use llvm-cov instead of gcov when compiler is clang.
   - if [ "$TRAVIS_OS_NAME" = "linux" ] && [ "$CC" = "clang" ]; then ln -sf $(which llvm-cov) /home/travis/bin/gcov; fi
 
diff --git a/src/version.c b/src/version.c
index ae28d08..a90d52e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -784,6 +784,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    841,
+/**/
     840,
 /**/
     839,