add ghc haskell and go version for e2

e2/e2.ghc.hs

@@ -0,0 +1,5 @@
+fibsum prev curr acc max	| curr > max = acc
+				| rem curr 2 == 0 = fibsum curr (prev + curr) (acc + curr) max
+				| otherwise = fibsum curr (prev + curr) acc max
+
+main = print (fibsum 1 1 0 4000000)

e2/e2.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	sum := 0
+	for prev, curr := 1, 1; curr <= 4000000; prev, curr = curr, prev+curr {
+		if curr%2 == 0 {
+			sum += curr
+		}
+	}
+	fmt.Println(sum)
+}