Update .travis.yml

.travis.yml

@@ -1,5 +1,5 @@
 dist: xenial
-osx_image: xcode10.2
+osx_image: xcode11.2
 language: cpp
 sudo: true
 
@@ -27,12 +27,10 @@ matrix:
     env: LUA=5.2
   - os: linux
     env: LUA=5.2
-  allow_failures:
-  - os: osx
 
 before_script:
 - if [ "$TRAVIS_OS_NAME" == "linux" ]; then sudo apt install -y liblua${LUA}-dev; fi
-- if [ "$TRAVIS_OS_NAME" == "osx" ] ; then brew link gettext --force; fi
+- if [ "$TRAVIS_OS_NAME" == "osx" ] ; then brew install glew --build-from-source; brew link gettext --force; fi
 - mkdir build
 - cd build
 
@@ -60,7 +58,6 @@ addons:
     - fmt
     - jpeg
     - gettext
-    - glew
     - libpng
     - lua
     - qt5