Enabled an alternate profile for building and testing against the old hadoop (1.0.x).

- also dropped support for Mac OS JDK 1.6 as it complicates the profiles
- added target to gitignore
Added the old build to travis.
Made it mvn clean test.
Merge pull request #76 from sjlee/sjlee-old-profile

enabling an alternate profile for building and testing against the old hadoop version