Add "auth0_hook" support and missing field on "auth0_client"

[yinzara]

Changes proposed in this pull request:

• Add new "auth0_hook" resource that uses the Auth0 Hooks API to create hooks (very similar to rules)
• Update resource_server test case and user resource for changes in auth0 golang library breaking changes

Output from acceptance testing:

$ make testacc TESTS=TestAccHook
==> Checking that code complies with gofmt requirements...
?   	github.com/terraform-providers/terraform-provider-auth0	[no test files]
=== RUN   TestAccHook
--- PASS: TestAccHook (1.80s)
PASS
coverage: 6.0% of statements
ok  	github.com/terraform-providers/terraform-provider-auth0/auth0	2.031s	coverage: 6.0% of statements
testing: warning: no tests to run
PASS
coverage: 0.0% of statements
ok  	github.com/terraform-providers/terraform-provider-auth0/auth0/internal/random	0.189s	coverage: 0.0% of statements [no tests to run]

And to prove

make testacc TESTS=TestAccResourceServer
==> Checking that code complies with gofmt requirements...
?   	github.com/terraform-providers/terraform-provider-auth0	[no test files]
=== RUN   TestAccResourceServer
--- PASS: TestAccResourceServer (2.58s)
PASS
coverage: 11.6% of statements
ok  	github.com/terraform-providers/terraform-provider-auth0/auth0	2.954s	coverage: 11.6% of statements
testing: warning: no tests to run
PASS
coverage: 0.0% of statements
ok  	github.com/terraform-providers/terraform-provider-auth0/auth0/internal/random	0.284s	coverage: 0.0% of statements [no tests to run]

 make testacc TESTS=TestAccClient
==> Checking that code complies with gofmt requirements...
?   	github.com/terraform-providers/terraform-provider-auth0	[no test files]
=== RUN   TestAccClientGrant
--- PASS: TestAccClientGrant (4.39s)
=== RUN   TestAccClient
--- PASS: TestAccClient (1.33s)
=== RUN   TestAccClientZeroValueCheck
--- PASS: TestAccClientZeroValueCheck (3.12s)
=== RUN   TestAccClientRotateSecret
--- PASS: TestAccClientRotateSecret (2.78s)
PASS
coverage: 27.5% of statements
ok  	github.com/terraform-providers/terraform-provider-auth0/auth0	11.856s	coverage: 27.5% of statements
testing: warning: no tests to run
PASS
coverage: 0.0% of statements
ok  	github.com/terraform-providers/terraform-provider-auth0/auth0/internal/random	0.369s	coverage: 0.0% of statements [no tests to run]

make testacc TESTS=TestAccUser
==> Checking that code complies with gofmt requirements...
?   	github.com/terraform-providers/terraform-provider-auth0	[no test files]
=== RUN   TestAccUserMissingRequiredParams
--- PASS: TestAccUserMissingRequiredParams (0.01s)
=== RUN   TestAccUser
--- PASS: TestAccUser (5.66s)
PASS
coverage: 21.4% of statements
ok  	github.com/terraform-providers/terraform-provider-auth0/auth0	5.934s	coverage: 21.4% of statements
testing: warning: no tests to run
PASS
coverage: 0.0% of statements
ok  	github.com/terraform-providers/terraform-provider-auth0/auth0/internal/random	0.188s	coverage: 0.0% of statements [no tests to run]

[yinzara]

I can't help it that auth0 rules and auth0 hooks have a very similar syntax and functionality. :) The CodeClimate errors about duplicate code is just because of how similar they are. How can I fix that?

[yinzara]

The Travis CI errors seem to all be related to a missing "client_secret" (i.e. the AUTH0_CLIENT_SECRET environment variable).

[yinzara]

I think you and I are literally working in tandem on all of this. lol I see my changes being reflected in master.

[alexkappa]

I can't help it that auth0 rules and auth0 hooks have a very similar syntax and functionality. :)

You have a point there :)

Don't worry about the codeclimate issues too much, I'll do a review and likely they won't be important. And don't worry about the travis build either, I have to run the tests manually as protected env vars are not available to pull requests.

I think you and I are literally working in tandem on all of this

Unfortunately, I beat you to the punch there. My apologies for this, I should have mentioned that I was working on it so you wouldn't have to. We're mid-transition over to terraform-providers/terraform-provider-auth0 and I'm trying to get a hang of having things in two places... I'll make sure to let people know if I'm working on something. Sorry again, and thanks for helping out