strongops: Add --license option for saving license

When the --license option is specified no authentication is done, but
the given license key is validated and then written to strongloop.json
if it is valid.

If a user also needs to use StrongOps, they can run the command without
the --license option to fill in the authentiction details.

Adds dependency on not-yet-releases strong-agent@0.4.13

SLN-1223 #refs
deps: patch bump deploy, pm, and supervisor

Non-breaking changes.
v2.7.2

 * deps: patch bump deploy, pm, and supervisor (Ryan Graham)

 * strongops: Add --license option for saving license (Ryan Graham)

 * package: alphabetize dependencies (Ryan Graham)

 * test: allow pre-release versions (Ryan Graham)

 * Fix broken doc link and small wording tweak (Rand McKinney)

 * slc: describe as "StrongLoop Controller" (Sam Roberts)

 * Fix old doc link (Rand McKinney)
Merge branch 'release/2.7.2'
Merge tag 'v2.7.2'

v2.7.2

 * deps: patch bump deploy, pm, and supervisor (Ryan Graham)

 * strongops: Add --license option for saving license (Ryan Graham)

 * package: alphabetize dependencies (Ryan Graham)

 * test: allow pre-release versions (Ryan Graham)

 * Fix broken doc link and small wording tweak (Rand McKinney)

 * slc: describe as "StrongLoop Controller" (Sam Roberts)

 * Fix old doc link (Rand McKinney)
deps: upgrade strong-build to 0.2.x

Includes changes in behaviour, not just bug fixes.
v0.2.8

 * deps: upgrade strong-build to 0.2.x (Ryan Graham)