Excluded tests,ext-lib and node-modules from code coverage

In ytestrunner command, added --cov-exclude=tests/**
--cov-exclude=ext-lib/** --cov-exclude=node_modules/**
Added missing dependencies list in .md file, updated ReadME.rst file with new options

Added xml-writer and ycb dependencies in README.md, new options in
ReadME.rst file
Added arrow quick installation guide
Reverting changes to package.json
Updated index.rst with arrow quick
ext-lib/
Merge branch 'master' of https://github.com/yahoo/arrow

 is necessary,
Resolved conflict
Resolved conflict, added space
Merge pull request #46 from pranavparikh/master

Added quick start tutorial , new options and dependencies in documentation ( resolved conflict)