Add support for new_host_delay in monitor definitions

[jszwedko]

This field defaults to 300 if empty, but we also need to support setting
it to 0 so I chose to use a *int pointer.

I stumbled upon #56 which discussed the use of pointers to support optional fields which seemed to be leaning towards the approach I took here, but let me know what you think.

TestCreateAndDeleteMonitor is failing locally for me, showing a diff including:

                        -  Handle: (string) "",
                        -  Id: (int) 0,
                        -  Name: (string) ""
                        +  Email: (string) (len=30) "[email protected]",
                        +  Handle: (string) (len=30) "[email protected]",
                        +  Id: (int) 222578,
                        +  Name: (string) (len=13) "Jesse Szwedko"

I can dig in more, but this also fails on master (first including the changes from #81) so I'm hoping I'm just doing something wrong when running the tests.

[ojongerius]

Nice one! Your implementation matches my preferred solution to #56. The acceptance test were failing, which was raised fixed in #73 / #85.

[ojongerius]

I originally started coding up the same implementation, but if your function is named Int, has as single purpose returning a pointer to an int (or it returns nil), why not change the signature to only accept an int like so?:

func Int(v int) *int { return &v }

(See https://github.com/zorkian/go-datadog-api/pull/83/files#diff-01127be9ed6b6352616a2f1c10bc3540R29 )

[jszwedko]

👍 I tend to agree. I'd borrowed the implementation from aws/aws-sdk-go (which I meant to call out in the PR description), but I think explicit is better.

[jszwedko]

Borrowed your implementation in c08c499

[ojongerius]

Thanks @jszwedko!