Spring Insight Beta 2.0

This change updates the build pack with changes needed to support
Spring Insight Beta 2.0.

Changes:
- Removed agent_id, agent_pass since this is no longer passed in
VCAP_SERVICES
credentials
- Added detecting agent_transport in VCAP_SERVICES.  If not present, it
will
default to ‘rabbitmq’. Also removed “hard coded’ HTTP transport
settings.
- Changed agent download URL detection and processing - Insight Service
broker
now returns full endpoint path instead of partial path.  Build pack no
longer has to
construct the download path.
- The Insight broker sets the label field in VCAP_SERVICES to
‘p-insight’.
Changed the buildpack’s detection logic to use this new label.
- Configuration of the Insight agent (i.e. password, username,
transport, etc.)
is now done via a properties file that is downloaded from the
Insight dashboard.  Removed from the build pack the agent configuration
code and added
code to put the new configuration property file into correct location.