1.6.0

• Add static qualifiers to json creators for onCompletion enum serialization.
• Corrected Exception message for Keccak-256 hash function.
• Add TEAL 3 support.
• Regenerated comment.
• Fix custom token key comment.
• Update .gitignore.
• Regenerate Indexer Client.
• Regenerate client code, implement new cucumber tests.
• Fix base32 decode bug.
• Add secure vars and docker login.
• Don't override values with lookupParams/suggestedParams.
• New constructors for v2 and Indexer that also accepts tokenKey.
• Updated README example.