Ember.ENV.EXTEND_PROTOTYPES - Cannot read property 'String' of undefined

Hey, after a recent update to the app I am receiving the following error: `Cannot read property 'String' of undefined`. I traced it down to a condition in the inflector's `addon/lib/ext/string.js`:

if (Ember.ENV.EXTEND_PROTOTYPES === true || Ember.ENV.EXTEND_PROTOTYPES.String) {
...
}

My environment does not have `EXTEND_PROTOTYPES` in it. It has the following, literally:

EmberENV: {
FEATURES: {
// Here you can enable experimental features on an ember canary build
// e.g. 'with-controller': true
}
}

What's the most odd here is that all the dependency versions are specific in `bower.json`, there're no `~` nor `^`:

{
"name": "frontend",
"dependencies": {
"ember": "2.6.0",
"ember-cli-shims": "0.1.1",
"ember-cli-test-loader": "0.2.2",
"ember-qunit-notifications": "0.1.0",
"bootstrap": "3.3.5",
"pretender": "1.1.0",
"Faker": "3.1.0",
"jsoneditor": "5.5.6",
"jquery-jsonview": "1.2.3",
"pace": "1.0.2"
}
}

as well as in `package.json`:

"devDependencies": {
"broccoli-asset-rev": "2.4.2",
"ember-ajax": "2.0.1",
"ember-bootstrap": "0.7.3",
"ember-cli": "2.6.2",
"ember-cli-app-version": "1.0.0",
"ember-cli-babel": "5.1.6",
"ember-cli-dependency-checker": "1.2.0",
"ember-cli-events-bus": "0.0.2",
"ember-cli-htmlbars": "1.0.3",
"ember-cli-htmlbars-inline-precompile": "0.3.1",
"ember-cli-inject-live-reload": "1.4.0",
"ember-cli-jshint": "1.0.0",
"ember-cli-moment-shim": "2.0.0",
"ember-cli-notifications": "3.3.1",
"ember-cli-pace": "0.1.0",
"ember-cli-pagination": "2.2.2",
"ember-cli-qunit": "1.4.0",
"ember-cli-release": "0.2.9",
"ember-cli-sri": "2.1.0",
"ember-cli-sticky": "0.6.1",
"ember-cli-uglify": "1.2.0",
"ember-data": "2.14.2",
"ember-export-application-global": "1.0.5",
"ember-json-editor-for": "1.1.3",
"ember-load-initializers": "0.5.1",
"ember-moment": "7.0.0-beta.3",
"ember-resolver": "2.0.3",
"ember-welcome-page": "1.0.1",
"loader.js": "4.0.1",
"ember-cp-validations": "3.3.2"
}

so I did not expect that a regular update would break the app! :(

Could you please help me out sorting the particular issue as well as share a link to a resource to help figuring out how to "freeze" the dependencies reliable so it is not that fragile all of the sudden?

Thank you!