Merge pull request #3 from aalong/master

Use standard Tempfile naming to avoid Sprockets conflict
Updated version and changes log for contribution to fix tempfile naming to avoid sprockets conflict
Ruby 2 compatibility fix, removed some lingering occurrences of RAILS_ROOT, clean up of gemspec file, no longer package unnecessary files like the test files
Fixed RAILS_ENV and use File.join instead of Rails.root.join
Rewrite README in RDoc format.

`README` has been rewritten in the RDoc format. The wording in several sections
was massaged to be more understandable, but no major changes were made. Same
deal with code examples.

As an aside: the documentation and code samples in some sections are *really*
bad. For example, the "attachment_fu migrations" section is barely
comprehensible.
Rename README -> README.rdoc

This has been done for two reasons:

* The file should render properly on GitHub w/a file extension.
* Adding a filename extension gives semantic info about the format of it's
  contents.

References to README were also corrected.
Merge pull request #4 from Ichimonji10/master

Update README
Thank you Ichimonji10 for this contribution!
Reformat README.

The README has been reformatted in the following ways:

1. Bare code samples have been wrapped in + or <code> tags as appropriate.
2. The large code sample in <h2>has_attachment(options = {})</h2> has been
   re-ordered so examples are sorted alphabetically.
3. The following transformations were applied to several code samples:

        foo :bar -> foo(:bar)
        { foo: :bar } -> {foo: :bar}

4. Other minor tweaks. Typo corrections and the like.
Add `*.swp` to .gitignore, for vim swapfiles.
Merge pull request #5 from Ichimonji10/master

minor fixes and restylings
Added S3 encrypted file support from cschulte22
Incorporated fixes from tricycle
Fixing test suite to work as gem