(QENG-760) support for additional disk for vagrant

- if a given vagrant box has a disk_path then either create a new vmdk
  disk or use the provided disk
- defaults to 50 x 1024 bytes if the disk needs to created
(QENG-775) Do not use puppet to stop puppet on older PE on SLES

A bug in the init script on older versions of SLES causes the init
script to kill our `puppet resource` invocation as well as the daemon
agent.
Merge pull request #307 from anodelman/maint

(MAINT) update nokogiri dependency
Merge pull request #306 from branan/qeng_775

(QENG-775) Do not use puppet to stop puppet on older PE on SLES
create 1.12.2 gem
Merge pull request #308 from anodelman/make-gem

create 1.12.2 gem
Merge pull request #303 from anodelman/vagrant-maint

(QENG-760) support for additional disk for vagrant
(MAINT) aws-sdk 1.43 breaks beaker specs

- pin to aws-sdk 1.42.0