Added test for c++ static_assert

see #68

Signed-off-by: Cristian Maglie <c.maglie@arduino.cc>

src/arduino.cc/builder/test/sketch_with_static_asserts/sketch_with_static_asserts.ino

@@ -0,0 +1,16 @@
+// https://github.com/arduino/arduino-builder/issues/68
+
+const int a = 10;
+const int b = 20;
+
+static_assert(a < b, "bar");
+
+void setup() {
+  test();
+}
+
+void loop() {
+}
+
+void test() {
+}

src/arduino.cc/builder/test/try_build_of_problematic_sketch_test.go

@@ -177,6 +177,10 @@ func TestTryBuild033(t *testing.T) {
 	tryBuild(t, "sketch_that_includes_arduino_h", "sketch_that_includes_arduino_h.ino")
 }
 
+func TestTryBuild034(t *testing.T) {
+	tryBuild(t, "sketch_with_static_asserts", "sketch_with_static_asserts.ino")
+}
+
 func makeDefaultContext(t *testing.T) map[string]interface{} {
 	DownloadCoresAndToolsAndLibraries(t)