v2.0.0-alpha6

What's Changed

• Bug/reify db failure by @zonotope in #160
• Fix garbage-collect-ledger http api by @cap10morgan in #166
• Fix single cardinality tempids by @cap10morgan in #168
• Allow setting the fluree.db log level w/ an env var by @cap10morgan in #178
• Update old snapshot format w/ :dbs to :ledgers when we read them in from disk by @cap10morgan in #179
• Feature: structured logging by @cap10morgan in #182
• Update upstream docker images by @cap10morgan in #180
• Fix shorter arities of validate-idx-continuity by @cap10morgan in #183
• FC-1431: fix/unresolve nodes by @zonotope in #191
• Add orderBy variable query tests by @cap10morgan in #193

Full Changelog: v2.0.0-alpha5...v2.0.0-alpha6