v0.3.4

• Add Guide to Pharmacology (#19, thanks @jsstevenson)
• Add OncoTree (#20, thanks @jsstevenson)
• Add Molecular Ontology Almanac (#21, thanks @jsstevenson)
• Add ChemIDPlus (#18, thanks @jsstevenson)
• Enforce all Bioregistry identifiers are actually in the database with new data integrity test