Remove the config for Travis CI (and thank them for their support!)

Signed-off-by: Cosmin Truta <ctruta@gmail.com>

.travis.yml

@@ -1,28 +0,0 @@
-branches:
-  except:
-    - /libpng[0-1][0-8]/
-    - /v[0-1][.][0-8][.][0-9]+/
-
-language: c
-
-os:
-  - freebsd
-  - linux
-  - osx
-
-env:
-  - AUTOMATION=cmake
-  - AUTOMATION=configure
-  - AUTOMATION=makefiles
-
-before_script:
-  - 'if test "$TRAVIS_OS_NAME" = "linux"; then export CI_CC="gcc"; else export CI_CC="clang"; fi'
-  - 'if test "$TRAVIS_OS_NAME" = "osx"; then export CI_CMAKE_GENERATOR="Xcode"; fi'
-  - 'if test "$TRAVIS_OS_NAME" != "osx"; then export CI_SANITIZERS="address,undefined"; fi'
-  - 'export CI_MAKEFILES="scripts/makefile.$CI_CC scripts/makefile.std"'
-  - 'export CI_MAKE_FLAGS=-j2'
-  - 'export CI_CMAKE_BUILD_FLAGS=-j2'
-  - 'export CI_CTEST_FLAGS=-j2'
-
-script:
-  - './ci/ci_verify_$AUTOMATION.sh'