Edge equality operator is incorrect

[nrkramer]

The current edge equality operator is this:

template <typename T>
bool operator==(shared<const Edge<T>> p1, shared<const Edge<T>> p2) {
  return p1->getNodePair().first->getUserId() ==
             p2->getNodePair().first->getUserId() &&
         p2->getNodePair().second->getUserId() ==       <<<< bad
             p2->getNodePair().second->getUserId();
}

This is incorrect, since the second user ids are not getting compared against each-other (we're comparing p2->getNodePair().second->getUserId() against itself).

This will be changed to:

template <typename T>
bool operator==(shared<const Edge<T>> p1, shared<const Edge<T>> p2) {
  return p1->getNodePair().first->getUserId() ==
             p2->getNodePair().first->getUserId() &&
         p1->getNodePair().second->getUserId() ==       <<<< good
             p2->getNodePair().second->getUserId();
}

To resolve this bug.

Edge equality is a core functionality of this library. Therefore I'm marking this as critical.

[sbaldu]

Yep, it's a typo, my bad. Thanks : )

[nrkramer]

Opened a PR here: #326