(pub): publish v0.1.2

- fixes ability to set jsonify to false
- fixes Illegal Invocation errors with the AsyncLocalStorage adaptor

- docs improvements
  - README only reports build status of master branch
  - adds more links in docs (mostly to storage engines)
  - adds CodeCov badge

- internal improvements
  - adds tests with 100% code coverage!
  - checks tests and code coverage w/ Travis and CodeCov
  - uses Node 10 Active LTS for CI
  - adds comment about shallow cloning

README.md

@@ -3,7 +3,7 @@
 <!-- releases / versioning -->
 [![package-json](https://img.shields.io/github/package-json/v/agilgur5/mst-persist.svg)](https://npmjs.org/package/mst-persist)
 [![releases](https://img.shields.io/github/tag-pre/agilgur5/mst-persist.svg)](https://github.com/agilgur5/mst-persist/releases)
-[![commits](https://img.shields.io/github/commits-since/agilgur5/mst-persist/v0.1.1.svg)](https://github.com/agilgur5/mst-persist/commits/master)
+[![commits](https://img.shields.io/github/commits-since/agilgur5/mst-persist/v0.1.2.svg)](https://github.com/agilgur5/mst-persist/commits/master)
 <br><!-- downloads -->
 [![dt](https://img.shields.io/npm/dt/mst-persist.svg)](https://npmjs.org/package/mst-persist)
 [![dy](https://img.shields.io/npm/dy/mst-persist.svg)](https://npmjs.org/package/mst-persist)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "mst-persist",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "Persist and hydrate MobX-state-tree stores",
   "main": "dist/index.js",
   "module": "dist/mst-persist.esm.js",