Remove outdated Travis file

.travis.yml

@@ -1,48 +0,0 @@
-language: csharp
-mono: none
-dotnet: 3.0.100-1
-dist: xenial
-
-branches:
-  only:
-    master
-
-env:
-  - RUNTIME=centos.7-x64
-  - RUNTIME=ol.7-x64
-  - RUNTIME=fedora.27-x64
-  - RUNTIME=fedora.28-x64
-  - RUNTIME=debian.8-x64
-  - RUNTIME=debian.9-x64
-  - RUNTIME=ubuntu.14.04-x64
-  - RUNTIME=ubuntu.16.04-x64
-  - RUNTIME=ubuntu.18.04-x64
-  - RUNTIME=opensuse.42.3-x64
-
-sudo: required
-
-git:
-  depth: false
-
-script:
-  - dotnet restore dotnet-packaging.sln
-  - dotnet pack dotnet-packaging.sln -c Release
-  - dotnet test Packaging.Targets.Tests/Packaging.Targets.Tests.csproj
-
-  - export NuGetPackageVersion=$(cat demo/version.txt)
-  - export PATH=$PATH:$HOME/.dotnet/tools
-
-  - dotnet tool install --global --add-source dotnet-tarball/bin/Release/ dotnet-tarball --version $NuGetPackageVersion
-  - dotnet tool install --global --add-source dotnet-zip/bin/Release/ dotnet-zip --version $NuGetPackageVersion
-  - dotnet tool install --global --add-source dotnet-rpm/bin/Release/ dotnet-rpm --version $NuGetPackageVersion
-  - dotnet tool install --global --add-source dotnet-deb/bin/Release/ dotnet-deb --version $NuGetPackageVersion
-
-  - cd $TRAVIS_BUILD_DIR/demo/aspnetcore
-  - dotnet restore
-  - if [ "$RUNTIME" = "rhel.7-x64" ]; then dotnet rpm -c Release -r rhel.7-x64 -f netcoreapp3.0; fi
-  - if [ "$RUNTIME" = "ubuntu.16.04-x64" ]; then dotnet deb -c Release -r ubuntu.16.04-x64 -f netcoreapp3.0; fi
-
-  - cd $TRAVIS_BUILD_DIR/demo/cliscd/
-  - dotnet restore
-
-  - ./run-tests.sh -r $RUNTIME