Decimal places at jitter and ping.

[servidge]

Some small adjustments in one pull request.

• Changed output type to stdout for --version and --csv-header. Addition to "send --json and --csv results to stdout and logs to stderr https://github.com/librespeed/speedtest-cli/pull/39"
• decimal places at jitter and ping, better values with --share, this limits/extended ping and jitter to .2 decimal places at --csv / --json and stdout. Also it prevents 1.0909090909090908 ping times within csv and json and extend those values in rest of the data. (the initial reason for the change)
• formatting, tabs, spaces and blank lines

[servidge]

Some of my modifications within the README.md are also contained in https://github.com/librespeed/speedtest-cli/pull/47 from the other side of the water. ;) The rest has no overlap.