Update NPM dependencies, setup Jest tests and CircleCI setup, fix pos…

…ition check based on tests

.babelrc

@@ -0,0 +1,3 @@
+{
+  "presets": [ "./tools/babel-preset" ]
+}

.circleci/config.yml

@@ -0,0 +1,40 @@
+# Javascript Node CircleCI 2.0 configuration file
+#
+# Check https://circleci.com/docs/2.0/language-javascript/ for more details
+#
+version: 2
+jobs:
+  build:
+    docker:
+      # specify the version you desire here
+      - image: circleci/node:7.10
+
+      # Specify service dependencies here if necessary
+      # CircleCI maintains a library of pre-built images
+      # documented at https://circleci.com/docs/2.0/circleci-images/
+      # - image: circleci/mongo:3.4.4
+
+    working_directory: ~/repo
+
+    steps:
+      - checkout
+
+      # Download and cache dependencies
+      - restore_cache:
+          keys:
+          - v1-dependencies-{{ checksum "package.json" }}
+          # fallback to using the latest cache if no exact match is found
+          - v1-dependencies-
+
+      - run: yarn install
+
+      - save_cache:
+          paths:
+            - node_modules
+          key: v1-dependencies-{{ checksum "package.json" }}
+
+      # run tests!
+      - run: yarn test
+
+      # send code coverage info to coveralls
+      - run: cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js

.gitignore

@@ -1,4 +1,5 @@
 .DS_Store
+coverage
 es
 node_modules
 umd

.npmignore

@@ -1,3 +1,4 @@
+coverage
 tools
 rollup.config.js
 *.sublime-project