Add CONTRIBUTING.md
Upgrade gem dependencies
Replace .rvmrc with .ruby-gemset
Update development gem dependencies to be bundler only
Upgrade gem dependencies
Upgrade mutant gem dependency
Update specs to require the file without the extension
Upgrade mutant gem dependency
Add devtools configuration file
Upgrade version to 0.0.3
Add default minimum and maximum length to LengthComparable classes
Add default minimum and maximum value to ValueComparable classes
Change Time minimum and maximum seconds to be clearer

* Use the actual integer range
Refactor range tests to use Range#cover?
Update Numeric types to be value comparable
Update flay and flog thresholds