Permissions on /etc/linaro are too restrictive

Issue Background

/etc/linaro only has execute permission for www-data

Issue description

Does kernelci try to see if kernelci-frontend.cfg exists before reading it, I've given it r-x group rights and then the DATE_RANGE in that file works. We need to check on the other settings in the files in that directory as to whether they might break other things if they don't work now and we change things so that they take effect. Our provision scripts don't create /etc/linaro so we probably need to, and set the permissions there.

Acceptance criteria