Fix typo in README.md

Remove additional word `support` which was repeated twice

[ci skip]
Issue 549:	A missing comma in a argument list should not prevent parsing
when tolerant:true

https://code.google.com/p/esprima/issues/detail?id=549
Update ESLint to 0.6.2.

https://code.google.com/p/esprima/issues/detail?id=473