Create BuildManager class and move post methods into it

This commit creates a TaskOrchestration::BuildManager class, which will
encompass the behavior of posting start and result class to the build server.
It has instance variables for the job_id, timeout, count, ref, downstream job,
and management server. This is another step toward moving the packaging repo's
functionality into discreet classes. This commit also slightly refactors
@branan's original post methods to behave from within the class instead of as
global methods availble to rake.

Signed-off-by: Moses Mendoza <moses@puppetlabs.com>
Add ENV overrides for @build.managed and @build.management_server

These could theoretically be useful as command line flags to a package build,
so we enable setting them via ENV['MANAGED'] and ENV['MANAGEMENT_SERVER'].

Signed-off-by: Moses Mendoza <moses@puppetlabs.com>
Dont actually curl, just say we are
Update check_var to return the variable being checked

This makes check_var slightly more useful for inline assignments. This is fully
backwards compatible.

Signed-off-by: Moses Mendoza <moses@puppetlabs.com>
Temporarily comment inaccessible methods
zz_managed