Make the test for info .. | eless work on Travis

[kaushalmodi]

https://travis-ci.org/kaushalmodi/eless/jobs/566054797#L565

[kaushalmodi]

Really odd..

On my machine for both versions 4.13 and 6.5 of info, info grep | eless -D shows this in the debug:

DEBUG: first_line_piped_data = File: grep.info-t, Node: Top, Next: Introduction, Up: (dir)

But on Travis, for info version 6.1, the same gives:

DEBUG: first_line_piped_data = Next: Introduction, Up: (dir)

Ref: https://travis-ci.org/kaushalmodi/eless/jobs/566098228#L485

Why??

[kaushalmodi]

OK, the issue was with info 6.1 that comes with xenial distribution on Travis.
Upgrading to the bionic distribution upgrades texinfo to 6.5 and that solves this problem.

[kaushalmodi]

Fixed in 2311386.