Update header.html
Giant octocats are terrifying.

set width to 64
center octocat
Merge pull request #13 from aerofoil/review

replace 'Aerofoil on GitHub' with octocat
make octocat a link to GitHub profile
update email addresses
- ignoring _site
- _site is local and will be build by github itself everytime a push is
  incoming
Merge branch 'master' into doc_submodule

* master:
  - ignoring _site - _site is local and will be build by github itself everytime a push is   incoming
  update email addresses
  make octocat a link to GitHub profile
  center octocat
  Giant octocats are terrifying.
  Update header.html