If redis client throws exception, don't raise it

For throttling, when the redis client throws an exception, the request
ends up getting rate limited. Modify this to be similar to how
ActiveSupport.MemCacheStore functions (the read, write and increment
methods do not raise exceptions)
Merge pull request #49 from wkimeria/wip/dont_raise_redis_error

If redis client throws exception, don't raise it
Version 3.0.0; update changelog
Better organize integration tests

Add rake tasks `test:units` and `test:integration`

Run integration tests by default on TravisCi.
Run memcached and redis on TravisCi.
Integration tests: less flakiness by sleeping more
[travisci] Fix Errno::ENETUNREACH errors in redis integration tests
[travisci] Add ruby 2.1.1 tests
Update changelog
Merge branch 'integration'
README: remove year from copyright.

h/t @fredbenenson
Implement Proxy for Dalli

kickstarter/rack-attack#52
Make Rack::Attack a class and Rack::Attack.new return an instance of that class, rather than Rack::Attack.
Merge pull request #53 from hakanensari/patch-1

Implement Proxy for Dalli
Update changelog
tests: add gemfiles for dalli 1.1.x and 2.x
Support older dalli client versions
Support a Dalli Connection Pool
Handle older Dalli clients
Delegate to class methods with forwardable
Tidy up defaults. We don't need to use ||= because this runs when the class gets loaded, and we won't have user supplied defaults yet.