Added alerts api support

[jkandasa]

@vnugent I have added alerts api support. Kindly review and merge it

[jkandasa]

Ticket: Add support for Alert API #15

[jkandasa]

@vnugent Does Hawkular Demo server update to date?

[FilipB]

Just a few general comments:

• some javadoc and comments would be definitely nice
• is there any reason not to log anything?
• not sure if this is doable everywhere but it's recommended to fix the code rather than using SuppressWarnings("unchecked")

[jkandasa]

@FilipB Thank you for your valuable feedback!

• Yes, We will add javadoc, I have added a ticket to track: Add javadoc #28
• We are using slf4j.Logger for main code https://github.com/jkandasa/hawkular-java-client/blob/master/src/main/java/org/hawkular/client/ClientResponse.java#L116 and for Test Reporter.log https://github.com/Hawkular-QE/hawkular-java-client/pull/26/files#diff-13879768ef5ecd0c98a9d2e48b3f7c87R116
• SuppressWarnings("unchecked") Yes, this not good but in some cases unable to avoid.

[vnugent]

Can you add the failing tests to the known-failure group, eg @Test(groups={"known-failure"})?

[jkandasa]

@vnugent marked alerts failure test cases with @Test(groups={"known-failure"})

[vnugent]

@jkandasa can you pull and rebase new changes I added to master? test in travis should pass with the new known-failure exclusion