Merge pull request #31 from wearp/master

Corrected CustomMiddleware example
Reference tinyindex in Docs; link to PyPI, not crates.io

[ci skip]
Merge pull request #33 from wearp/master

Added to Query.search method & tests
Fix hash value of QueryRegex
Reword unclear section on storage limitations

[ci skip]
Fix _last_id after opening old DB (closes #34)
Label regression tests
Add documentation for Query.search

[skip ci]
Rename Query.search to Query.contains
Version bump to v2.1.0