Update the sym method

When obfuscate is called, it doesn't necessarily have to obfuscate.
In that case, the sym method should just return the original sym
name, and not raise an exception.
Add rubymine project directory to .gitignore
Merge pull request #5 from jvazquez-r7/ignore_idea

Add rubymine project directory to .gitignore
Merge pull request #4 from rapid7/update_sym_method

Update the sym method
Bump gem version to rebuild.
Merge branch 'master' into gh-pages
Update docs.