Takes care of rounding errors

Both Math.cbrt() and Math.sqrt() return floats with rounding
errors. Rounding off to 4 digits precision seems to be good enough and
makes the specs pass.
Uses Hamls built in html escaping
Merge pull request #28 from valtech/master

Small bugfixes
fix warn on install for asking https
installing nokogiri
Merge pull request #32 from twillouer/master

Little change for ubuntu installers - thanks William.
Create LICENSE.md
Updates dependencies
Removes rspec deprecation stub => double
Updates ruby version in readme
Moves from .rvmrc to .ruby-version

Note from RVM:
You are using '.rvmrc', it requires trusting, it is slower and it is not
compatible with other ruby managers, you can switch to '.ruby-version'
using 'rvm rvmrc to [.]ruby-version' or ignore this warning with 'rvm
rvmrc warning ignore /Users/duksis/code/extreme_startup/.rvmrc',
'.rvmrc' will continue to be the default project file in RVM 1 and
RVM 2, to ignore the warning for all files run 'rvm rvmrc warning ignore
all.rvmrcs'.
Merge pull request #33 from duksis/dependencies

Updates outdated dependencies - thanks Hugo.
Merged in upstream improvements