Add ability to handle spaces in names

[awiddersheim]

Allow for using usernames and schedules that contain spaces by encapsulating them in either single or double quotes. For example:

hubot> pager trigger "Foo Bar" testing

[stephenyeargin]

😻

[awiddersheim]

@stephenyeargin Hopefully we can get this merged and into a new release?

[stephenyeargin]

Published as v2.1.15

[awiddersheim]

@stephenyeargin Awesome! Thanks!