Remove Conan builds from travis-CI

.travis.yml

@@ -285,19 +285,6 @@ matrix:
               packages: ['clang-6.0', 'libstdc++-8-dev']
       env: COMPILER='clang++-6.0' CPP17=1 EXAMPLES=1 COVERAGE=1 EXTRAS=1
 
-    # 8/ Conan
-    - language: python
-      python:
-        - "3.7"
-      dist: xenial
-      install:
-        - pip install conan-package-tools
-      env:
-        - CONAN_GCC_VERSIONS=8
-        - CONAN_DOCKER_IMAGE=conanio/gcc8
-      script:
-        - python .conan/build.py
-
 install:
   - DEPS_DIR="${TRAVIS_BUILD_DIR}/deps"
   - mkdir -p ${DEPS_DIR} && cd ${DEPS_DIR}