Merge ~jocave/plainbox-provider-snappy/+git/plainbox-provider-snappy-parts:add-getpcaps-pkg into ~checkbox-dev/plainbox-provider-snappy/+git/plainbox-provider-snappy-parts:master

[Jonathan Cave]

Kernel security tests require getpcaps which may have been removed in core18

diff --git a/snapcraft.yaml b/snapcraft.yaml
index 77a61a4..7336ca3 100644
--- a/snapcraft.yaml
+++ b/snapcraft.yaml
@@ -45,6 +45,7 @@ parts:
             - iw
             - iperf3
             - libasound2
+            - libcap2-bin
         build-packages:
             - linux-headers-generic
             - libcap-dev