Made the Rails version with whitelisting explicit

A 'later version' of Rails was described, but this confused me a little.
I just made the Rails version explicit. Whitelisting was added in Rails 3.2.
Merge pull request #127 from tilsammans/patch-1

Made the Rails version with whitelisting explicit
remove mocha to fix travis failures
Merge pull request #129 from orend/remove-mocha-to-fix-travis-failures

remove mocha to fix travis failures
Use the instrumentation framework to instrument unpermitted params.

Similarly to rails/rails, use the instrumentation framework to instrument unpermitted params. The event name is compatible with this in rails/rails to allow easy migration to rails 4.0
Merge pull request #131 from orend/instrument-event-on-unpermitted-params

Use the instrumentation framework to instrument unpermitted params.
add travis CI and gem version badges
Merge pull request #132 from orend/add-badges

add badges
Implements require with multiple parameters

Normal use is unchanged.

When used with multiple parameters the error raised in case a
parameter is missing lists all the missing parameters.

Returns the params hash if no required parameters are missing.
Merge pull request #117 from d-Pixie/master

Allow multiple keys in call to require
Revert "Implements require with multiple parameters" -- too confusing an API.

This reverts commit 7758a3446879f27b1932eef81adb116659266218.
fix Travis link [ci skip]
Merge pull request #133 from frodsan/fix_README

fix Travis link [ci skip]
Bump version
Document how to require multiple keys in params

With reference to commit 735da78f6e570a076820cb0edd23e38c1837e5b2
Merge pull request #146 from josephers/patch-1

Document how to require multiple keys in params
link to the Rails guide section about strong_parameters.