Updated JSON version to fix Ruby 2.2.0 compatibility issue.
Updated JSON version to fix Ruby 2.2.0 compatibility issue.

In Ruby 2.2.0, a C function was changed into a macro which caused
and issue with expansion in the JSON gem (find out more here:
https://github.com/flori/json/issues/229). This was fixed in
JSON 1.8.2, so we need to update taskwarrior-web gemspec to use
later versions of JSON.

dancollins/taskwarrior-web,dancollins/taskwarrior-web,theunraveler/taskwarrior-web,theunraveler/taskwarrior-web,theunraveler/taskwarrior-web,dancollins/taskwarrior-web