Change 2017 GSoC report activity yaml

[hritikhks]

This fixes the previously 0 based yaml and changes it to 1 based.

Fixes #616

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[li-boxuan]

Please amend your commit message. You should not put everything on one line (commit head).

[li-boxuan]

Your commit message does not reflect your changes. This file is not 2017 report but 2018.

[123vivekr]

Also your commit message should follow the commit guidelines.

[shikharvaish28]

Thanks for working on this!
Codewise, it LGTM though your commit message is not according to our guidelines. It is too long which is not preferred. I would suggest to make it according to the length mentioned in https://api.coala.io/en/latest/Developers/Writing_Good_Commits.html . The main commit message should just include the important details and the rest of the things can be included in the commit description.

Also, you might want to make changes into other branches since they would prevent your master branch from messing up and also allow you to do multiple issues/PR at the same time.