Update logger.js

Fixed missing context object...

Author: rwhite-lightbox

lib/logger.js

@@ -94,11 +94,11 @@ exports.config = (config, levels) => {
     },
     context: (context) => {
       return {
-        remaining:
+        remaining: context &&
           context.getRemainingTimeInMillis &&
           context.getRemainingTimeInMillis(),
-        function: context.functionName && context.functionName,
-        memory: context.memoryLimitInMB && context.memoryLimitInMB,
+        function: context && context.functionName && context.functionName,
+        memory: context && context.memoryLimitInMB && context.memoryLimitInMB,
       };
     },
     custom: (custom) =>