Provide baseDir to allow for proper caching

[wongpeiyi]

See ember-cli/ember-cli-htmlbars#90 – there is a deprecation warning with Ember 2.7:

DEPRECATION: ember-cli-htmlbars is opting out of caching due to an AST plugin that does not provide a caching strategy: `touch-action`

Also clean up jshint warnings:

modules/ember-hammertime/mixins/touch-action.js: line 32, col 16, A constructor name should start with an uppercase letter.
modules/ember-hammertime/mixins/touch-action.js: line 6, col 3, 'Handlebars' is defined but never used.