Squashed 'lib/plank/' content from commit b3c7592

git-subtree-dir: lib/plank
git-subtree-split: b3c75928552fd99c4eda60e9b6b9375f8c2bd75a
Merge commit 'f2d2d4af2db1878015802a16c610192f581f1641' as 'lib/plank'
removed lib plank
Squashed 'plank/' content from commit b3c7592

git-subtree-dir: plank
git-subtree-split: b3c75928552fd99c4eda60e9b6b9375f8c2bd75a
Merge commit '6a97c449a986cc4b974ef710a65ae9b649de1194' as 'plank'
remove traverse, using plank
Squashed 'lib/traverse/' content from commit e563bf5

git-subtree-dir: lib/traverse
git-subtree-split: e563bf5d261676c2a5da5c2c489a5805745db25b
Merge commit '67d7a98f2b5da5733f1b868e19fc00f2339b5289' as 'lib/traverse'
fixed tests