add support to run test using travis

Author: ivandrofly

.travis.yml

@@ -4,7 +4,7 @@ dotnet: 2.0.3
 mono: none
 dist: trusty
 install:
-  - nuget restore C-Sharp-Algorithms.sln
-#  - nuget install xunit.runners -Version 2.3.1 -OutputDirectory testrunner
+  - dotnet restore
 script:
-  - dotnet restore
+  - dotnet build
+  - dotnet test UnitTest/UnitTest.csproj