update ci.yml

.travis.yml

-language: cpp
+language: csharp
 sudo: required
 dist: trusty
+solution: CAP.sln
+dotnet: 2.1.0
 
 matrix:
   include:
@@ -10,33 +12,9 @@ matrix:
   - os: osx
     osx_image: xcode8.3 # macOS 10.12
     
-env:  
-  global:
-    - DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
-    - DOTNET_CLI_TELEMETRY_OPTOUT: 1
-    - CLI_VERSION=2.0.0
-  
-addons:  
-  apt:
-    packages:
-    - gettext
-    - libcurl4-openssl-dev
-    - libicu-dev
-    - libssl-dev
-    - libunwind8
-    - zlib1g
-    
-# Make sure build dependencies are installed.
-before_install:  
-  - if test "$TRAVIS_OS_NAME" == "osx"; then ln -s /usr/local/opt/openssl/lib/libcrypto.1.0.0.dylib /usr/local/lib/; ln -s /usr/local/opt/openssl/lib/libssl.1.0.0.dylib /usr/local/lib/; fi
-  - export DOTNET_INSTALL_DIR="$PWD/.dotnetcli"
-  - export PATH="$DOTNET_INSTALL_DIR:$PATH"  
-  
-install:
-  - travis_retry curl -sSL https://dot.net/v1/dotnet-install.sh | bash /dev/stdin --channel 2.0 --version "$CLI_VERSION" --install-dir "$DOTNET_INSTALL_DIR"
-
 # Run the build script
 script:
   - dotnet --info
-  - dotnet restore
-  - dotnet test test/DotNetCore.CAP.Test/DotNetCore.CAP.Test.csproj -f netcoreapp2.0
+  - dotnet restore CAP.sln
+  - dotnet build CAP.sln
+  - dotnet test test/DotNetCore.CAP.Test/DotNetCore.CAP.Test.csproj