(build) Update Travis to .NET Core 2.1.4 SDK
(build) Update Travis to .NET Core 2.1.4 SDK

daveaglick/cake,ferventcoder/cake,vlesierse/cake,mholo65/cake,vlesierse/cake,gep13/cake,devlead/cake,ferventcoder/cake,mholo65/cake,cake-build/cake,gep13/cake,devlead/cake,patriksvensson/cake,patriksvensson/cake,robgha01/cake,Sam13/cake,cake-build/cake,daveaglick/cake,robgha01/cake,Sam13/cake