v0.3.0

PointNeighbors v0.3.0

Diff since v0.2.3

Merged pull requests:

• Implement neighborhood search based on static neighbor lists (#9) (@efaulhaber)
• Move cell list management to a new struct (#12) (@efaulhaber)
• Revise periodic box API (#30) (@efaulhaber)
• Replace all references to "particle" by "point" (#31) (@efaulhaber)
• Implement copy_neighborhood_search to allow empty "template" neighborhood search (#32) (@efaulhaber)
• Merge breaking changes from dev (#33) (@efaulhaber)