attach and view a proof for a particular standard

* add ability to attach one proof for one standard with integration
tests
* restrict proof route to everything but index
* redesign homepage and users#show page
Merge pull request #11 from akshatpradhan/manage_requirements

attach and view a proof for a particular standard
replaced standard with requirements model
renamed spec helpers and factories
Merge pull request #18 from super-engineer/master

rename Standard scaffold with Requirement scaffold
add code coverage analysis tool
Merge pull request #24 from akshatpradhan/coverage

add code coverage analysis tool
update readme with more information

* update README
* add license (GPL v3)
* add screenshot of homepage
Merge pull request #26 from akshatpradhan/readme

update readme with more information
user attaches proofs and only sees their proofs

This features allows proofs to be assigned only to a specific user.

We’re currently using a hidden_field with user_id on `proofs#new`.
However, we’re not entirely sure if that’s best practices. Rails guides
says that nesting user, proofs, requirements is bad practice, so we
couldn’t do something like `form_for [@user, @proof, @requirement]`
Merge pull request #20 from akshatpradhan/user_proofs2

user attaches proofs and only sees their proofs