fix uncaught exception when using AdBlocker

The problem was that when file was blocked by AdBlocker
The code tried to convert Error into Response object,
which caused uncaught exception.

version 0.19.0

add public method `respond`

add `caseSenstive` options to routes #38

version 0.16.5

update version

fix handling of binary data in FileSystem

add local worktree to npm ignore

version 0.16.1

version 0.16.0