remove redundant profile and plugin.

oss-parent project provides `sonatype-oss-release` profile to
sign jar file, so we do not have to make original profile.

* https://github.com/sonatype/oss-parents/blob/oss-parent-7/pom.xml
* http://lacostej.blogspot.jp/2011/01/publishing-your-signed-oss-project-to.html

this profile will be active when we execute `maven-release-plugin`.
format pom.xml
Grundlefleck: minor tidy-up and method reshuffling.
Grundlefleck: switch project to java source level of 5.0, in line with the source level of FindBugs itself. Fixes #6.
Bump version of junit used, to the sane one that doesn't bundle hamcrest.
Spike for issue #11
Ignore swap files.
Add travis configuration.
Add travis ci build status.
Fix mangled travis config.
Merge pull request #10 from eller86/suggestion-to-shorten-pom

Suggestion to shorten pom, and skip needless maven-gpg-plugin execution
Grundlefleck: bump version tested with to 1.3.9, 1.3.8 and earlier will no longer be supported. I have my doubts that they ever worked, but didn't spend too much time thinking about it.
Declare the dependency on FindBugs as a range. Put a hard requirement on FindBugs releases between 1.3.9 and 2.0.2.
support both of FindBugs 1.3.9 and 2.0.2.
install FindBugs 2.0.2 before build.
Merge pull request #12 from eller86/support-version-2

Looks good. Thanks!
Remove unused method.
Fix typo, registarar -> registrar.
Whoops. Reinstate removed method. Forgot it was a compile time dependency for a later FB version.
Add a comment to explain why the unused warning has been suppressed.