Add a class to represent myria relation keys
myrial parser returns RelationKeys
Add some type assertions to myrial interpreter
Create RelationKey instances in fakedb ingest
Remove shebang line from interpreter.py
Add hash function to RelationKey
Fix argument names in fakedb
Fix myrial optimizer tests
Use RelationKey for datalog Scan operations
Fix output of raco.tests
Remove redundant relation key functionality from myrialang.py
Use RelationKey in the root Store operation
Merge branch 'master' into andrew_relation_key
Fix myrial script
Fix external iterate
relation_key: use *args instead of **kwargs

In order to let us construct relations using 1 or 3 arguments
to the constructor

Signed-off-by: Daniel Halperin <dhalperi@cs.washington.edu>
Merge pull request #91 from uwescience/andrew_relation_key2

Regularize relation keys in raco; redux