Option to disable colours in output of bootstrap.sh

[branfosj]

While reviewing easybuilders/easybuild-easyconfigs#12366

I get the following in my log output:

^[[0;34m==>^[[0m ^[[0;33mpython3 -m pip install --no-cache-dir -q --upgrade pip --target=external/^[[0m
^[[0;34m==> [+pygelf]^[[0m ^[[0;33mpython3 -m pip install --no-cache-dir -q -r /dev/shm/branfosj-admin/eb-_tfssomv/tmp.kXMJRhBcEI --target=external/ --upgrade^[[0m
^[[0;34m==> [+docs]^[[0m ^[[0;33mpython3 -m pip install --no-cache-dir -q -r docs/requirements.txt --target=external/ --upgrade^[[0m

Can you add one of the following:

• option to disable colour output in bootstrap.sh
• detection of when colour output will display correctly