Filter modified to prevent mongo error

The filter on the health data array now checks
for null values. This resulted in an error since
we were inputting multiple nulls into the same
db.

Author: mdtagg

chronos_npm_package/controllers/healthHelpers.js

@@ -220,7 +220,7 @@ healthHelpers.collectHealthData = async() => {
   return Promise.all(healthDataCollection).then(array => {
     // console.log("PROMISE ARRAY",array)
     return array.filter(metric => {
-      if (isNaN(metric.value) || metric.value === 'NaN' || metric.value === '') return false;
+      if (isNaN(metric.value) || metric.value === 'NaN' || metric.value === '' || metric.value === null) return false;
       else return true;
     })
   }