(maint) Changing rescue of Exception to StandardError

Rescuing exception is in general a bad practice and can cause undesired behaviors.

A detailed discussion about this can be found here: https://github.com/puppetlabs/puppet/pull/1925#discussion_r6529813
(maint) Remove constant and requires now provided in spec_helper
(maint) Factor a duplicated constant up to spec_helper
Merge pull request #1952 from jjulien/fix_exception

(maint) Changing rescue of Exception to StandardError
Merge pull request #1967 from kylog/maint/one-more-fixup-for-already-initialized-constant-warning

Maint/one more fixup for already initialized constant warning
Doc cleanup on create_resources example

The two items in the hash must be separated by a comma and group isn't a valid parameter to the user resource.
(doc) Merge branch 'nibalizer-patch-1' into stable

* nibalizer-patch-1:
  Doc cleanup on create_resources example

Documentation only update, merging into stable.
Merge branch 'stable'

* stable:
  Doc cleanup on create_resources example
Merge branch 'master' of https://github.com/puppetlabs/puppet