Add tasks for all the new languages

Task/Roman-numerals-Decode/Phix/roman-numerals-decode.phix

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+constant romans = "MDCLXVI",
+         decmls = {1000,500,100,50,10,5,1}
+
+function romanDec(string s)
+integer n, prev = 0, res = 0
+    for i=length(s) to 1 by -1 do
+        n = decmls[find(s[i],romans)]
+        if n<prev then n = 0-n end if
+        res += n
+        prev = n
+    end for
+    return res
+end function