Update Travis jdk from 6 to 7 [#75]

In Hadoop 2.x recommended version of java is 7, let's test on travis
using jdk7.
Merge pull request #80 from ravwojdyla/master

[#79] Revert absolute path for bash_completion scripts
Merge pull request #78 from ravwojdyla/jdk7

Update Travis jdk from 6 to 7 [#75]
Bump to version 2.4.7
Add sphinx to developer requirements
Add .DS_Store to gitignore
Don't swallow tracebacks when commands fail.
[#72] Fix for count invalid behavior - use length

Instead of printing space used ('spaceConsumed') from count request
respond, use 'lenght' field. Length field holds space before
replication. This makes snakebite output the same stats as default
hdfs client.
Merge pull request #84 from ravwojdyla/dev

Add sphinx to require and update gitignore
Merge pull request #85 from Julian/master

Don't swallow tracebacks when commands fail.
Merge pull request #87 from ravwojdyla/fix_count

[#72] Fix for count invalid behavior - use length