[EC2] Update default Spark version to 1.2.0

[nchammas]

Now that 1.2.0 is out, let's update the default Spark version.

[nchammas]

cc @JoshRosen

[SparkQA]

Test build #24787 has started for PR 3793 at commit ec0e904.

• This patch merges cleanly.

[JoshRosen]

It looks like this was already done in branch-1.2, but it doesn't hurt to do it in master: dfb8c65

If it's not already there, we should add this to the "preparing a release" checklist on the wiki.

[nchammas]

Hmm, master is already on 1.3.0 in that config file in dfb8c65.

[SparkQA]

Test build #24787 has finished for PR 3793 at commit ec0e904.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[AmplabJenkins]

Test PASSed.
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[JoshRosen]

That other config change is for documentation generation; we can't bump the EC2 version to a snapshot release. This looks good to me.

[nchammas]

Oh, hold up, we need to update this map, too...

[SparkQA]

Test build #24790 has started for PR 3793 at commit 3255832.

• This patch merges cleanly.

[SparkQA]

Test build #24790 has finished for PR 3793 at commit 3255832.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[AmplabJenkins]

Test PASSed.
Refer to this link for build results (access rights to CI server needed):
https://amplab.cs.berkeley.edu/jenkins//job/SparkPullRequestBuilder/24790/
Test PASSed.

[JoshRosen]

Probably also want to have 1.1.1 in here since it's also in branch-1.2; I'll just add this myself on merge, though.

[JoshRosen]

LGTM, so I'll merge this into master (1.3.0).