First pass at #15.

* Better type checking should prevent any error messages
  when `wp cli cmd-dump` returns invalid json.
* TODO: file a bug report with wp-cli about this.
Adds Exclude patterns to CTags generation.

Fixes #16.
Removes the loading echo messages.

Fixes #14.

* Note: The Ctags generation messages are still present.
Bumps version to 0.1.16.
Updates changelog for 0.1.16
Build 0.1.16
Merges branch 'release/0.1.16' into develop