adds a health service for determining the status of the workers

This commit adds a health service which ensures that at least
one worker is active. Uses `isActive()` to determine if the
worker is ready. The health service runs on a seperate address.
Will return a HTTP 200 if health, HTTP 500 otherwise.

Fixes #192

Signed-off-by: Alex Price <[email protected]>

1 files changed, 3 insertions, 0 deletions

diff --git a/state.go b/state.go
index bf88f012..98451f48 100644
--- a/state.go
+++ b/state.go
@@ -14,6 +14,9 @@ type State interface {
 
 	// NumJobs shows how many times worker was invoked
 	NumExecs() int64
+
+	// IsActive returns true if worker not Inactive or Stopped
+	IsActive() bool
 }
 
 const (