Squashed commit of the following:

commit 88d50ccdeb0be3056bddf3a5be3ea13f193a99de
Author: max <bmx007@gmail.com>
Date:   Tue Sep 24 17:30:06 2013 +0100

    remove require ruby-prof in specs.

commit 29ba5d497a5e35ae70edc4f96f45b9f7b6c8a1ab
Author: max <bmx007@gmail.com>
Date:   Tue Sep 24 17:21:59 2013 +0100

    Profile bulk tube creation benchmark.

commit 5d0dae8c865a4e51423290af7e002ed19bfed441
Author: max <bmx007@gmail.com>
Date:   Tue Sep 24 16:42:36 2013 +0100

    Add empty tube bulk creation benchmark.

commit 6a82805aad3f86febdf1e40d5f8433ece6a4ee1c
Author: max <bmx007@gmail.com>
Date:   Tue Sep 17 09:32:57 2013 +0100

    Update lims-core version.
Fix tube benchmark specs.
Update core version to speed up uuid generation.
Update core and api to speedup uuid creation.
Merge pull request #69 from maxigit/57980394_speed_up_uuid_creation

57980394 speed up uuid creation