Resolve "fix README about tested OS"

Closes #71

See merge request !65

Resolve "prepare release 2.0.0"

Closes #70

See merge request !64

Resolve "add debian9 support"

Closes #55

See merge request !63

Resolve "remove puppet4 acceptance tests"

Closes #63 and #69

See merge request !62

Resolve "declare private classes as private"

Closes #67

See merge request !61

Resolve "use schedure resource instead of cron"

Closes #57

See merge request !55

Resolve "core update can be done in an idempotent way"

Closes #66

See merge request !60

Resolve "remove :: usage"

Closes #65

See merge request !59

Resolve "update a resource can be not idempotent"

Closes #64

See merge request !58

Resolve "set manual release job"

Closes #62

See merge request !57

Resolve "pin RUBYGEMS_VERSION"

Closes #61

See merge request !56

Resolve "prepare release 1.3.5"

Closes #60

See merge request !54

Resolve "puppet lower limit"

Closes #59

See merge request !53

Resolve "add release stage  in gitlab CI"

Closes #58

See merge request !52

Resolve "add puppet6 support"

Closes #56

See merge request !51

Resolve "use bundle instead of pdk to run tests"

Closes #53

See merge request !49

Resolve "enable rubocop"

Closes #51

See merge request !48

Resolve "enable beaker debug"

Closes #52

See merge request !47

Resolve "build module with pdk 1.7.0"

Closes #50

See merge request !46