Added new callbacks to action.

[AlfonsoUceda]

Added prepend_before, prepend_after, append_before and append_after.

Closes #76

[jodosha]

@AlfonsoUceda Thank you! This looks great for me. 👍

[AlfonsoUceda]

I didn't introduce more tests, I think is enough

[coveralls]

Coverage increased (+0.01%) to 99.11% when pulling 3320ea0 on AlfonsoUceda:master into 8c299e8 on lotus:master.

[jodosha]

@joneslee85 and @weppos Do you mind to review this?

[weppos]

One concern. I wonder if the primary method should be append_before and the alias before, rather than the opposite, for consistency with prepend_before.

[jodosha]

@weppos That was mine too. Now we're two people concerned with it. 👍 for this change.
If there isn't any stopping point, this should be released on tomorrow as v0.3.2.

[AlfonsoUceda]

ok @jodosha and @weppos I'm going to do that change ;) 👍 for the change

[coveralls]

Coverage increased (+0.01%) to 99.11% when pulling 0f751e6 on AlfonsoUceda:master into 8c299e8 on lotus:master.

[runlevel5]

me like, me 👍

[jodosha]

@AlfonsoUceda I've merged this, thank you! 👍

[weppos]

Thanks @AlfonsoUceda for the work. 👏

[AlfonsoUceda]

you welcome mates ;)