refactor: replace deprecated String.prototype.substr() (#1782)

* refactor: replace deprecated String.prototype.substr()

.substr() is deprecated so we replace it with .slice() which works similarily but isn't deprecated

Signed-off-by: Tobias Speicher <rootcommander@gmail.com>

* Resolve PR comment

Signed-off-by: Tobias Speicher <rootcommander@gmail.com>

docs/lcd-i2c-PCF8574.md

@@ -33,7 +33,7 @@ var board = new five.Board();
 board.on("ready", function() {
 
 
-  var random = Math.random().toString(36).replace(/[^a-z]+/g, "").substr(0, 4).toUpperCase();
+  var random = Math.random().toString(36).replace(/[^a-z]+/g, "").slice(0, 4).toUpperCase();
 
   // Controller: PARALLEL (default)
   var p = new five.LCD({

eg/lcd-all.js

@@ -4,7 +4,7 @@ var board = new five.Board();
 board.on("ready", function() {
 
 
-  var random = Math.random().toString(36).replace(/[^a-z]+/g, "").substr(0, 4).toUpperCase();
+  var random = Math.random().toString(36).replace(/[^a-z]+/g, "").slice(0, 4).toUpperCase();
 
   // Controller: PARALLEL (default)
   var p = new five.LCD({

eg/lcd-i2c-PCF8574.js

@@ -4,7 +4,7 @@ var board = new five.Board();
 board.on("ready", function() {
 
 
-  var random = Math.random().toString(36).replace(/[^a-z]+/g, "").substr(0, 4).toUpperCase();
+  var random = Math.random().toString(36).replace(/[^a-z]+/g, "").slice(0, 4).toUpperCase();
 
   // Controller: PARALLEL (default)
   var p = new five.LCD({

lib/led/ledcontrol.js

@@ -674,7 +674,7 @@ const Controllers = {
           throw new Error("The `row` method is only supported for Matrix devices");
         }
         if (typeof val === "number") {
-          val = (`0000000000000000${parseInt(val, 10).toString(2)}`).substr(0 - (this.columns), this.columns);
+          val = (`0000000000000000${parseInt(val, 10).toString(2)}`).slice(0 - (this.columns));
         }
         if (arguments.length === 2) {
           val = row;