Adds libssl-dev refs #1931

Author: JJ

shippable.yml

@@ -2,6 +2,7 @@ build:
   pre_ci:
     - wget https://github.com/nxadm/rakudo-pkg/releases/download/v2018.03-01/rakudo-pkg-Ubuntu14.04_2018.03-01_amd64.deb
     - dpkg -i *.deb
+    - apt-get install libssl-dev
     - PATH=~/.perl6/bin:/opt/rakudo-pkg/bin:$PATH && export PATH
     - install-zef-as-user && zef --/tap-harness --depsonly install .