Finalised datomic-testing macro.
Tag tests
* transactions for multiple tags
All tests passing
* Added placeholders for functions.
* Decided to not manually input negative ids for datomic transactions.  Too high, the risk of collision is.
* Changed interface to and from make-add functions.  Should probably rename them.  Too tired right now.
* Make place addition function.  Also made a sister function that does the actual transaction.  Easier to test.
* Added tests.