Add tests for Perl and Turning detection

test/fixtures/turing.t

@@ -0,0 +1,19 @@
+% Accepts a number and calculates its factorial
+
+function factorial (n: int) : real
+    if n = 0 then
+        result 1
+    else
+        result n * factorial (n - 1)
+   end if
+end factorial
+
+var n: int
+loop
+    put "Please input an integer: " ..
+    get n
+    exit when n >= 0
+    put "Input must be a non-negative integer."
+end loop
+
+put "The factorial of ", n, " is ", factorial (n)