For convenience, charts are now automatically released after each spec if they are not acquired using `persistent: true`. Also remove the confusing and error prone `chartInstance` global variable and make sure that chart instances are local to each spec.
Change the linter in gulp tasks to be consistent with Code Climate results which are based on ESLint using .eslintrc options. However, defaults Code Climate rules are too strict, so turn as warnings the 'complexity' and 'max-statements' rules (other errors has been fixed). Note that the Gulp task name has been changed for `gulp lint`.
* Better default tick rotation and tick autoskip settings
* scale.time: Use ctx to measure label, and <= instead of < for unit fitting
* Test Changes
* Passing Tests with new defaults
Updated unit tests to use correct 'boxes' property of chart instance. Tests did not require numerical updates!
Added a test to cover placing a full width box.
