lint fix (#16)

Author: gaantunes

postgres_mixin/config.libsonnet

@@ -1,5 +1,5 @@
 {
   _config+:: {
-    postgresExporterSelector: '',    
+    postgresExporterSelector: '',
   },
 }

postgres_mixin/dashboards/postgres-overview.json

@@ -1327,7 +1327,7 @@
         "definition": "label_values(pg_up, job)",
         "hide": 0,
         "includeAll": true,
-        "label": "job",
+        "label": "Job",
         "multi": true,
         "name": "job",
         "options": [],
@@ -1361,7 +1361,7 @@
         "definition": "label_values(pg_up{job=~\"$job\"},instance)",
         "hide": 0,
         "includeAll": true,
-        "label": "instance",
+        "label": "Instance",
         "multi": true,
         "name": "instance",
         "options": [],
@@ -1386,7 +1386,7 @@
         "definition": "label_values(pg_stat_database_tup_fetched{job=~\"$job\",instance=~\"$instance\",datname!~\"template.*|postgres\"},datname)",
         "hide": 0,
         "includeAll": true,
-        "label": "db",
+        "label": "Database",
         "multi": false,
         "name": "db",
         "options": [],