Added support for environments without tty

[knih]

This is an PR adding support to avoid truncating trees in environments without tty and resolves issue #173 simply.

jline2 creates an UnsupportedTerminal in environments that do not have a tty, but it has a column size of 80.

[knih]

Build failed due to the following reason:

Expected feature release number in range of 9 to 14, but got: 8

Installing oraclejdk8
$ export JAVA_HOME=~/oraclejdk8
$ export PATH="$JAVA_HOME/bin:$PATH"
$ ~/bin/install-jdk.sh --target "/home/travis/oraclejdk8" --workspace "/home/travis/.cache/install-jdk" --feature "8" --license "BCL"
Ignoring license option: BCL -- using GPLv2+CE by default
install-jdk.sh 2019-07-17
Expected feature release number in range of 9 to 14, but got: 8
The command "~/bin/install-jdk.sh --target "/home/travis/oraclejdk8" --workspace "/home/travis/.cache/install-jdk" --feature "8" --license "BCL"" failed and exited with 3 during .

[jrudolph]

Thanks for the PR, @knih. I'm going to address it when I'll be working on the next release.

Build failed due to the following reason:

Yeah, seems Travis doesn't support oraclejdk8 in all configs any more.