added GETTING_STARTED.md, updated README.md
added "Email" chapter
added:
link to Rubygems.org
some space in code-blocks;
headers size were changed.
some minor insertions
Merge pull request #65 from Sergey-Russiyan/develop

added GETTING_STARTED.md, updated README.md
Update README.md
Update README.md
Update .travis.yml
implemented singleton for webpage
fixed error with self.class
Update README.md
Update .travis.yml
final implementation
Update spec_helper.rb
Update howitzer
Update howitzer_spec.rb
probs
Update howitzer_spec.rb
fixed link heading to GETTING_STARTED.md file (it were directed to my clone project)
added "More information" chapter with 3 links.
unit tests