Fix minor typo
Update README with JavaScript troubleshooting solutions

These changes update the README to add a new solution for fixing dependency errors related to npm, bower, and grunt.

The error described in the README happened in when I ran grunt bower:update in engines/bastion.
The README now has an additional command for fixing these sorts of errors.
Fix README section for updating bower components

These changes fix a typo where the original author had likely meant replace "update" in the command with "install."
Fix grammar in README section text

This change matches the wording used in related section *Installing a New Dependency*
Reorganize dependency errors section of README

This change moves the *Example Dependency Errors* section above the section *Fixing Dependency Errors* so that the reader finds the more common errors with their exact fixes before the list of generalized commands that may or may not fix their error.

**Other changes include:**

- Add reference links between the two re-organized sections to facilitate troubleshooting.
- Add notes regarding the use of the `grunt bower:update` command as well as when it should be run.
- Make section heading text match style of related sections by using appropriate capitalization as well as revising their length to have fewer words.