ENH : GH11729 added index parameter in series to_string
Fixes #11729 
Please Review .

pls add a whatsnew note (enhancements is ok)
 @varun-kr can you update
 @jreback  Updated code . Please review .

It seems that there is some problem with the build . 
ERROR: test_get_all_data (pandas.io.tests.test_data.TestYahooOptions) is failing for many builds.
 just push again; the option tests occasionally fail
 @jreback  Done. 
 @varun-kr thanks!

can you open an issue to re-examine whether passing `index=False` should add those leading spaces (I think not).
