Add tasks for all the new languages

Task/Remove-duplicate-elements/Swift/remove-duplicate-elements-1.swift

@@ -0,0 +1 @@
+println(Array(Set([3,2,1,2,3,4])))

Task/Remove-duplicate-elements/Swift/remove-duplicate-elements-2.swift

@@ -0,0 +1,10 @@
+func uniq<T: Hashable>(lst: [T]) -> [T] {
+  var seen = Set<T>(minimumCapacity: lst.count)
+  return lst.filter { x in
+    let unseen = !seen.contains(x)
+    seen.insert(x)
+    return unseen
+  }
+}
+
+println(uniq([3,2,1,2,3,4]))

Task/Remove-duplicate-elements/Swift/remove-duplicate-elements-3.swift

@@ -0,0 +1,12 @@
+func uniq<T: Equatable>(lst: [T]) -> [T] {
+  var seen = [T]()
+  return lst.filter { x in
+    let unseen = find(seen, x) == nil
+    if (unseen) {
+      seen.append(x)
+    }
+    return unseen
+  }
+}
+
+println(uniq([3,2,1,2,3,4]))