add error logging to healtcheck

src/oncall/healthcheck.py

@@ -4,6 +4,9 @@
 from falcon import HTTPNotFound, HTTPInternalServerError
 from . import db
 
+import logging
+logger = logging.getLogger('oncall.app')
+
 
 class HealthCheck(object):
 
@@ -29,11 +32,13 @@ class HealthCheck(object):
                 cursor.close()
                 connection.close()
             except:
+                logger.exception('failed to query DB for healthcheck')
                 raise HTTPInternalServerError()
             try:
                 with open(self.path) as f:
                     status = f.readline().strip()
             except:
+                logger.error('could not find healthcheck file')
                 raise HTTPNotFound()
         resp.content_type = 'text/plain'
         resp.body = status