Update .travis.yml

Author: VJalili

.travis.yml

@@ -2,10 +2,10 @@ os:
     - linux
 matrix:
     include:
-        -	mono: none
+        -
             dotnet: 3.0
             install: ['dotnet restore']
             language: csharp
-            mono: none	
+            mono: none
             script: ['dotnet build', 'dotnet test GeUtilities.Tests/GeUtilities.Tests.csproj']
             solution: GeUtilities.sln