moved exercises beneath common package

exercises/01-wc/go.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"code.google.com/p/go-tour/wc"
+	"strings"
+)
+
+func WordCount(s string) map[string]int {
+	wc := make(map[string]int)
+	for _, v := range strings.Fields(s) {
+		wc[v] += 1
+	}
+	return wc
+}
+
+func main() {
+	wc.Test(WordCount)
+}