v0.3.1-alpha

• Add fullstack example
• Add ability to insert facts as Datomic-style entity maps
• Add support for arbitrary predicate s-expressions in value slot of rule expressions
• Update fact-index based on Clara's retract-facts-logical event in listeners.cljc. Fixes instances where multiple :one-to-one facts could come into existence with no warning
• Throw error if ever an insert logical request would violate the cardinality of a :one-to-one attribute
• Eliminate using identical accumulators in rules generated by entities macro
• Fix bug where a fact with a value slot of nil was not parsed into a Tuple records