[travis] Add build test for examples
The examples are excluded from the workspace, so we need to add the
command to build them.
@@ -28,3 +28,5 @@ before_install:
script:
- cargo build --all --verbose
- cargo test --all --verbose
+ - cargo build --all --verbose --manifest-path imgui-examples/Cargo.toml
+ - cargo build --all --verbose --manifest-path imgui-glium-examples/Cargo.toml
