Fix travis - analyzer and source_span updates (#975)

- Fix some new implicit cast warnings.
- Adjust expectations for new source_span output.

In version `1.5.0` of `source_span` the output for multi-line spans was
updated to output the content and highlight a section with lines on the
left instead of the old `^^^^^` format. Update the expectations
accordingly to expect that a bit of the multi-line content is printed.