Fix type decompose (ohler55#204)

Fix user defined jp unary operators

Identify field names that start with '_' as private

Lint (ohler55#201)

* Update linter to v2.0

* Add release notes

Update CI

Fixed issue 197 (ohler55#198)

Jp proc (ohler55#196)

* Start on procedures

* Add jp-proc tests

Precision (ohler55#191)

Fix precision on parsing.
Remove goveralls as it no longer provides accurate data.

Expr walk (ohler55#188)

* Determine function to walk expr matches and allow modification
* Add reflection to child, nth, and wildcard
* Add descent and filter to expr.Walk

Non string map keys (ohler55#186)

* Fix non-string map keys bug

* Release notes