Fix for handling multiple strategies

Following issue #307 in hapijs, it is necessary to use the scheme name
as the second parameter to Boom.unauthorized().

Added test for multiple strategies
add set/clear key for cookie
100% coverage and only key validation

key should at least be a non-empty string
Fix style issues
Merge remote-tracking branch 'upstream/master'

Conflicts:
	test/index.js
Merge pull request #29 from davegb3/fix-multiple-strategies

Fix for handling multiple strategies
Merge pull request #30 from Icehunter/master

add set/clear key for cookie
Cleanup for #30
Adds session keepalive support. Closes #35
Consistent credentials return
Correct cache.item.account to cache.account
Merge pull request #36 from paulovieira/master

Correct cache.item.account to cache.account
Fix clearInvalid
Merge pull request #37 from jdarling/master

Fix clearInvalid (for issue #34)
Simplify clearInvalid test
hapi 8 and invalid bug. Closes #39. Closes #40
typo
cache api change