travis: use opencv-4.1.0 & stackage lts-13.25

.travis.yml

@@ -31,7 +31,7 @@ addons:
 # The different configurations we want to test. You could also do things like
 # change flags or use --stack-yaml to point to a different file.
 env:
-- ARGS="--jobs 2 --resolver nightly-2018-12-21" CACHE_NAME=NIGHTLY_2018_12_21_CV_3_4_5
+- ARGS="--jobs 2 --resolver lts-13.25" CACHE_NAME=LTS_13_25_CV_4_1_0
 
 before_install:
 - sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y

stack.yaml

@@ -4,9 +4,12 @@ packages:
 - opencv-examples/
 - opencv-extra/
 - opencv-extra-examples/
-flags: {}
+flags:
+  opencv:
+    opencv4: true
+  opencv-extra:
+    opencv4: true
 allow-newer: true
-
 extra-lib-dirs:
 - /usr/local/lib
 

travis-build-opencv

@@ -1,7 +1,7 @@
 #!/bin/bash
 set -eux -o pipefail
 
-OPENCV_VERSION=${OPENCV_VERSION:-3.4.5}
+OPENCV_VERSION=${OPENCV_VERSION:-4.1.0}
 
 GRAPHICAL=${GRAPHICAL:-OFF}