Adding methods to allow to get UUIDs with random MAC address

[alessandrozucca]

Added two methods that allow to get a UUID v1/v2 with a randomised MAC address.

In the existing NewV1() and NewV2() the MAC address is only randomised when the network card is not found.

NewV1RandomMAC()
NewV2RandomMAC()

Reasons:
We want to use UUID v1 so that the timestamp can be used to find the right partition quickly (when a table is partitioned by time)

At the same time we don't want to expose the MAC address for security reasons.

#64

[coveralls]

Coverage increased (+0.4%) to 96.939% when pulling bcea4fa on intelligentpos:IPL-147/random-mac-address into 5bf94b6 on satori:master.

[coveralls]

Coverage increased (+0.4%) to 96.939% when pulling e9aca44 on intelligentpos:IPL-147/random-mac-address into 5bf94b6 on satori:master.

[coveralls]

Coverage increased (+0.4%) to 96.939% when pulling d80f1d2 on intelligentpos:IPL-147/random-mac-address into 5bf94b6 on satori:master.

[geototti21]

Looks very useful

[docmerlin]

This is great, its especially necessary when in docker containers on separate machines not in some sort of orchestration setup.