Include upstream minor fixes, get rid of wheezy workaround
small bugfixes See merge request shared-puppet-modules-group/postfix!21
Recent versions of the concat module error out when one passes an ensure parameter.
Adujst master.cf template for Debian Stretch: support Dovecot 2.x. Closes #13 See merge request shared-puppet-modules-group/postfix!17
implement ensure absent for postfix::config See merge request shared-puppet-modules-group/postfix!16
Same as commit 3ee64eb, applied to the debian-9 template.