Fix logger regression.

Author: XhmikosR

lib/logger.js

@@ -6,7 +6,7 @@ const index = require('..');
 module.exports = () => logDriver({ level: getLogLevel() });
 
 function getLogLevel() {
-  if (index.options.verbose || Boolean(process.env.NODE_COVERALLS_DEBUG)) {
+  if (index.options.verbose || process.env.NODE_COVERALLS_DEBUG == 1) {
     return 'debug';
   }