use a const to prevent repetition

autometrics/src/constants.rs

@@ -1,3 +1,6 @@
+// Version of the autometrics spec we are targeting
+pub const AUTOMETRICS_SPEC_TARGET: &str = "1.0.0";
+
 // Metrics
 pub const COUNTER_NAME: &str = "function.calls";
 pub const HISTOGRAM_NAME: &str = "function.calls.duration";

autometrics/src/labels.rs

@@ -33,7 +33,7 @@ impl BuildInfoLabels {
             service_name: &get_settings().service_name,
             repo_url,
             repo_provider,
-            autometrics_version: "1.0.0"
+            autometrics_version: AUTOMETRICS_SPEC_TARGET
         }
     }
 

autometrics/src/tracker/prometheus.rs

@@ -148,7 +148,7 @@ impl TrackMetrics for PrometheusTracker {
                     build_info_labels.service_name,
                     build_info_labels.repo_url,
                     build_info_labels.repo_provider,
-                    "1.0.0" // autometrics_version
+                    AUTOMETRICS_SPEC_TARGET
                 ])
                 .set(1);
         });