Merge pull request #67 from scarf-sh/ISSUE-53-Do-not-track

[ISSUE-53] DO_NOT_TRACK

README.md

@@ -157,6 +157,11 @@ Alternatively, you can set this variable in your environment:
 export SCARF_ANALYTICS=false
 ```
 
+You can also set this variable in accordance to the [Console Do Not Track](https://consoledonottrack.com/) standard: 
+```shell
+export DO_NOT_TRACK=1
+```
+
 Either route will disable Scarf for all packages.
 
 #### I distribute a package on npm, and scarf-js is in our dependency tree. Can I disable the analytics for my downstream dependents?

report.js

@@ -55,7 +55,7 @@ function logIfVerbose (toLog, stream) {
 // SCARF_NO_ANALYTICS was the original variable, we'll get rid of it eventually
 const userHasOptedOut = (rootPackage) => {
   return (rootPackage && rootPackage.scarfSettings && rootPackage.scarfSettings.enabled === false) ||
-    (process.env.SCARF_ANALYTICS === 'false' || process.env.SCARF_NO_ANALYTICS === 'true')
+    (process.env.SCARF_ANALYTICS === 'false' || process.env.SCARF_NO_ANALYTICS === 'true' || process.env.DO_NOT_TRACK === '1')
 }
 
 const userHasOptedIn = (rootPackage) => {