Fix security warnings

Changes

• Updated debug@~2.3.0 to ~2.6.9
• Updated coveralls@~2.11.1 to ~2.13.3

Update debug dependency to avoid usage of package ms < 0.7

ms is vulnerable to regular expression denial of service (ReDoS) when extremely long version strings are parsed.
This is fixed with versions of ms > 0.7. The newer versions of debug use a version of ms > 0.7

Thanks to @Konkrad

Added type check for delay argument

v0.3.1

bump patch version

Release 0.3.0 (API changes)

• Allow application to assign event ID
• Added confirm() method and ev.maxRetries to enable notification retries.
• Added chageDelay() method to modify expiration time of a scheduled event.
• Added peek() method to peek event information and expiration time.
• Now all async calls return Promise (if callback is not supplied)

See README.md for more details.

v0.1.6

• Added more tests. Test coverage is now 100% !!
• Fixed a couple of minor bugs.
• Fixed all jshint errors.

v0.1.5

• Fixed bug in lua code that caused suggesting long interval that setTimeout cannot handle (thanks to Kyle)

v0.1.3

• Test coverage improvement
• Minor bug fixes found during the coverage improvement

v0.1.2

• Added support of node@0.8.x (removed the use of '^' in versions in dependency versions)
• Added node 0.8 to travis.

v0.1.0

• Added cancel method
• Modified callback arg for 'event' from array to and object (one event at a time)
• Updated reade, autobuild (travis) support, etc.