update links to breadboard tester

ch1-intro-arduino/index.html

@@ -238,7 +238,7 @@ <h2>testing the S4D breadboard</h2>
   <youtube ytid="79HmnUWkw9Q"/></youtube> 
 
     <p>The breadboard tester can be downloaded from <a href="https://github.com/HANICA/S4D-BreadboardTester">its home page here</a>.
-    You can also use this button: <download buttontext="download Breadboard Tester" href="https://github.com/HANICA/S4D-BreadboardTester/archive/master.zip"></download></p>
+    You can also use this button: <download buttontext="download Breadboard Tester" href="https://github.com/HANICA/S4D-BreadboardTester/raw/master/breadboard_tester.zip"></download></p>
 
   <h3>1.7: test your breadboard</h3>
   <p>Test your breadboard with the test program.</p>
@@ -294,7 +294,7 @@ <h2>the breadboard header file</h2>
   <section class="assignment">
     <h3 class="assignment questions">1.10: using the header file</h3>
     <p>The header file is part of the breadboard tester that you can download using the link above. 
-    But if you just need the header file, you can use this link to get it: <a href="https://raw.githubusercontent.com/HANICA/S4D-BreadboardTester/d3a0b498d8321900bc3c999f48f76e915bcd3449/breadboard_tester/s4d_breadboard.h" >s4d_breadbord.h</a> (rechtermuisknop => "Save Link As..." (o.i.d.))</p>
+    But if you just need the header file, you can use this link to get it: <a href="https://github.com/HANICA/S4D-BreadboardTester/raw/master/breadboard_tester/s4d_breadboard.h" >s4d_breadbord.h</a> (rechtermuisknop => "Save Link As..." (o.i.d.))</p>
     <ul>
       <li>Take the blinking program you wrote for exercise 1.8.</li>
       <li>Add the breadboard header file.</li>