Fix wget ERROR: The certificate of `....' is not trusted on linux debian

if you use wget  wget https://downloads-packages.s3.amazonaws.com/debian-7.7/gitlab_7.6.2-omnibus.5.3.0.ci.1-1_amd64.deb

ERROR: The certificate of `downloads-packages.s3.amazonaws.com' is not trusted.
ERROR: The certificate of `downloads-packages.s3.amazonaws.com' hasn't got a known issuer.

use

sudo apt-get install ca-certificates 

for fix it