Alpine 3.7 doesnt have git 2.18 available

[TheMacStack]

the alpine base may need to be updated to alpine 3.8 so git 2.18 is the default.
git 2.15 in alpine 3.7 has known security vulns
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-11233

[dtzar]

This is implemented with the 2.10.0 version of the image.