Update .travis.yml

.travis.yml

@@ -75,9 +75,6 @@ script:
     wait
     set +u # This is needed to continue Travis build
 matrix:
-  # TODO: Remove failure allow once linux works with 3.0
-  allow_failures:
-    - os: linux
   # We can use fast finish, as we don't need to wait for allow_failures builds to mark build as success
   fast_finish: true
   include:
@@ -86,7 +83,8 @@ matrix:
     - os: linux
       # Ref: https://docs.travis-ci.com/user/reference/bionic
       dist: bionic
+      dotnet: 3.0.100 # For linux, we need absolute dotnet version until https://travis-ci.community/t/is-net-core-3-0-supported/5630 is resolved
     - os: osx
       # Ref: https://docs.travis-ci.com/user/reference/osx
       dotnet: 3.0.100 # For OSX, we need absolute dotnet version until https://github.com/dotnet/core-setup/issues/4187 is resolved
-      osx_image: xcode11
+      osx_image: xcode11.2