Let Travis post to #build Slack room
Move scoverage into "coverage" profile in pom

Code coverage can now be generated by:
```
    mvn package -P coverage
    mvn scoverage:report
```

It will also be generated when running under Travis CI (by checking the TRAVIS
environment variable).
Merge pull request #240 from ryan-williams/slack

Let Travis post to #build Slack room
Merge pull request #243 from hammerlab/move-scoverage-to-profile

Move scoverage into "coverage" profile in pom
shade and relocate guava dependency to avoid conflicts
upgrade spark to 1.2; upgrade adam and associated fixes
add key to sort on and use external sorting
mix countbyvalue steps
deleting extra code