v0.2.6

TreeAMR v0.2.6

Diff since v0.2.5

Merged pull requests:

• Folds over points: mesh_fold and block_fold (M15) (#28) (@eschnett)
• Compare NaNs as one pattern in the flat-launch bit-for-bit test (#29) (@eschnett)
• Release 0.2.6 (#30) (@eschnett)