[SPARK-6643][MLLIB] Implement StandardScalerModel missing methods

[Lewuathe]

This is the sub-task of SPARK-6254.
Wrap missing method for StandardScalerModel.

[viirya]

uses mean or not -> uses std or not?

[SparkQA]

Test build #29545 has finished for PR 5310 at commit 82683a0.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.
• This patch does not change any dependencies.

[Lewuathe]

@viirya Thank you for comment. I updated.

[SparkQA]

Test build #29672 has finished for PR 5310 at commit a38f155.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.
• This patch does not change any dependencies.

[mengxr]

@Lewuathe The wrapper doesn't do anything different that StandardScalerModel. Do we really need it?

[Lewuathe]

@mengxr Yes. If I think again, it is unnecessary. Thank you for pointing out. I updated.

[mengxr]

LGTM. Let's retry Jenkins.

test this please

[mengxr]

test this please

[SparkQA]

Test build #29817 has finished for PR 5310 at commit bd31a64.

• This patch fails Python style tests.
• This patch merges cleanly.
• This patch adds no public classes.
• This patch does not change any dependencies.

[mengxr]

@Lewuathe You need an extra empty line to pass python style checker. Try dev/lint-python on your local and see the error message.

[Lewuathe]

@mengxr I updated. Thank you!

[SparkQA]

Test build #30073 has finished for PR 5310 at commit fafd690.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.
• This patch does not change any dependencies.

[mengxr]

Merged into master. Thanks!