v1.8.0

Features

• retry global cache operations on transient errors (#603) (5d6b650), closes #601

Bug Fixes

• don't return None for entities found in queries (#612) (9e5e255), closes #586
• fix bug with compressed blob property (#615) (d305f9f), closes #602
• fix failing unit test (#607) (5d3927e), closes #606
• handle unpickling between GAE NDB (2.7) to Cloud NDB (3) (#596) (5be4225)
• mock call to tasklets.sleep in unit test (#609) (00e23f3), closes #608
• prevent mismatch error when using default namespace on ancestor queries (#614) (ae67f04)
• reimplement _clone_properties (#610) (e23f42b), closes #566
• replicate legacy behavior for using cache with queries (#613) (edd1185), closes #586
• support int as base type for BooleanProperty (#624) (a04bf3a)