Add tasks for all the new languages

Task/Test-a-function/Nim/test-a-function-2.nim

@@ -0,0 +1,26 @@
+import unittest
+
+proc reverse(s): string =
+  result = newString(s.len)
+  for i,c in s:
+    result[s.high - i] = c
+
+proc isPalindrome(s): bool =
+  s == reverse(s)
+
+when isMainModule:
+  suite "palindrome":
+    test "empty string":
+      check isPalindrome ""
+
+    test "string of length 1":
+      check isPalindrome "a"
+
+    test "string of length 2":
+      check isPalindrome "aa"
+
+    test "string of length 3":
+      check isPalindrome "aaa"
+
+    test "no palindrome":
+      check isPalindrome("foo") == false