Metron accepts dropsonde messages, signs, and forwards to LS.

[#75375304]

Signed-off-by: Joseph Rodriguez <jrodriguez@pivotallabs.com>
Add template and spec for metron to listen for dropsonde [#75375304]

Signed-off-by: Joseph Rodriguez <jrodriguez@pivotallabs.com>
Use customizable AgentListener context name

[#75375304]

Signed-off-by: Joseph Rodriguez <jrodriguez@pivotallabs.com>
Merge branch 'develop'