Update getRandomNode() to work with credentials:

[advait]

• Providing credientials in the form:

    new Cassandra\Database([
      '192.168.0.2:8882' => [
        'username' => 'admin',
        'password' => 'pass',
      ], 'my_keyspace');

  as the documentation suggests previously failed due to the use of array_shuffle which squashes non-numerical keys into int indexes.

• This commit fixes the issue by using array_rand which preserves the keys.

[evseevnn-zz]

Previously, the logic was:

If one node does not fit, then try the following and to report that the connection settings a node specified is not correct.

If no node is not approached, then to report that none of the node does not have the correct parameters.

hmm ...

You suggest, while clean and not try to find the correct the connection settings to the node ....

My argument would be that look correct settings node: When adding a new node to the cluster, a typo will have less serious consequences.

However, the likelihood that someone who will add a new node makes a mistake is very small.

ok. Please bring an argument in support of his decision.

[advait]

I tried to preserve the logic of the previous implementation. The main reason for this pull request is to fix #14. I will address your comments in a second. Thoughts?

[evseevnn-zz]

fixed in b106851