feat(circonus/check): Check tags are configurable in config file

Add configuration key to CirconusConfig named "CheckTags"
Add logic to NewMetricDestination to add any user-configured check tags
to the existing array

issue #CIRC-8707

* Tags: check tag bundle conf

config/config.go

@@ -223,6 +223,7 @@ type CirconusConfig struct {
 	Broker          string            `toml:"broker"`
 	Hostname        string            `toml:"-"`
 	CheckSearchTags []string          `toml:"check_search_tags"`
+	CheckTags       string            `toml:"check_tags"`
 	DebugAPI        bool              `toml:"debug_api"`
 	CacheNoVerify   bool              `toml:"cache_no_verify"`
 	CacheConfigs    bool              `toml:"cache_configs"`
@@ -430,6 +431,12 @@ var agentConfig = `
     ## Note: cache_dir must be read/write for the user running the cua process
     # cache_dir = "/opt/circonus/etc/cache.d"
 
+    ## Check tags configurations
+    ## Optional
+    ## tags to add to the check bundle, in comma-deliminated namespace:tag pairs
+    ## eg: "team:red,team:blue,env:dev,security:pci,security:sox"
+    # check_tags = "foo:bar,baz:buzz"
+
     ## Debug circonus api calls and trap submissions
     ## Optional 
     # debug_api = true

internal/circonus/circonus.go

@@ -364,6 +364,11 @@ func NewMetricDestination(opts *MetricDestConfig, logger cua.Logger) (*trapmetri
 		checkTags = append(checkTags, getOSCheckTags()...)
 	}
 
+	if ch.circCfg.CheckTags != "" {
+		confCheckTags := strings.Split(ch.circCfg.CheckTags, ":")
+		checkTags = append(checkTags, confCheckTags...)
+	}
+
 	checkTarget := hostname
 
 	instanceLogger := &Logshim{