fix: Resolve package.json for version metadata regardless of nesting

[Thorn1089]

The package.json file appears at a different relative location in the source tree versus the compiled package.
It should be resolved regardless of the level of nesting present in the calling module.

Relates to #173

[coveralls]

Coverage increased (+0.04%) to 94.359% when pulling db41b53 on TomRK1089:feat/message-pact into a2d64b7 on pact-foundation:feat/message-pact.

[mefellows]

Awesome - thanks for this! I'll push out a new alpha shortly...

[mefellows]

hmm, merge build failed: https://travis-ci.org/pact-foundation/pact-js/builds/368919159?utm_source=email&utm_medium=notification

It's ok as it's not critical, but something to address when you/I get a moment.

[mboudreau]

@mefellows Why would the path change on release?

[Thorn1089]

Yes I just noticed the Jest tests were failing (somehow missed that when running locally). Trying to investigate now.

[Thorn1089]

@mboudreau When the logger.ts module is referencing the package.json, its relative path is ../../package.json as the module is under src/common. After compilation, logger.js is under common (no more src directory) and thus the relative path fails when using the published version of the module.

[Thorn1089]

@mefellows trying again in #175 and seeing if Travis agrees with what I see in npm test locally now.