Merge branch 'master' into tgorkin/gatsby-examples

* master: (82 commits)
  fix typo in performance.md
  pydeck: ArcLayer, BitmapLayer, ColumnLayer examples (#4189)
  [React] fix missing key error (#4193)
  [Bug] Fix hexagon layer projection (#4173)
  Remove HtmlWebpackPlugin from examples/playground (#4178)
  @deck.gl/json: Fix bug dropping props with falsy values (#4185)
  Fix buffer size check in Attribute.updateBuffer (#4190)
  Bump luma dependency (#4191)
  data-filter: support double precision (#4163)
  Use int type for enum uniforms (#4171)
  [TileLayer] fix tile indices generation in edge cases (#4170)
  v8.1.0-alpha.1
  Voodoo fix for Mac+NVIDIA bug (#4166)
  Remove unnecessary code from project glsl (#4162)
  Fix H3HexagonLayer update when viewport jumps (#4158)
  Refactor render tests; use stricter pass criteria (#4157)
  [Extension] Add source_target to brushing mode (#4150)
  Add offset feature to PathStyleExtension (#4126)
  Project module: support pre-projected positions (#4140)
  Repeat maps at low zoom levels (#4105)
  ...