Add octopus.push.package step support

[ss-remygreinhofer]

This patch implements the support for Octopus
(https://octopus.com/docs/api-and-integration/teamcity). It allows to
define a new type of build step: "octopus.push.package".

[cvbarros]

Hello @ss-remygreinhofer , sorry for not getting to this sooner! Thanks a lot for your contribution - however, would it be possible to add some tests that cover the usage for the new step type?

Recently, I'm trying to refactor tests to testify suites in order to deal with some isolation and cleanup issues I've had in the past. Take a look at 7ef46f9 and if you need any help adding test scenarios, let me know!

[ss-remygreinhofer]

No problem, I'll work on some testify tests.

[ss-remygreinhofer]

I just rebased my branch and although Travis gives me the green mark, the tests fail on my machine:

$ go test -v ./...
[...]
=== RUN   TestAgentRequirement_Create
--- FAIL: TestAgentRequirement_Create (0.00s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x58 pc=0x134074a]

goroutine 63 [running]:
testing.tRunner.func1(0xc000125a00)
	/usr/local/Cellar/go/1.11.5/libexec/src/testing/testing.go:792 +0x387
panic(0x13bf540, 0x173fb40)
	/usr/local/Cellar/go/1.11.5/libexec/src/runtime/panic.go:513 +0x1b9
github.com/cvbarros/go-teamcity-sdk/teamcity_test.createTestBuildTypeInternal(0xc000125a00, 0x0, 0x14287b5, 0x14, 0x1425043, 0xb, 0x10e0001, 0x156b058)
	/Users/remygreinhofer/go/src/github.com/cvbarros/go-teamcity-sdk/teamcity/build_type_test.go:272 +0x1aa
github.com/cvbarros/go-teamcity-sdk/teamcity_test.createTestBuildTypeWithName(0xc000125a00, 0x0, 0x14287b5, 0x14, 0x1425043, 0xb, 0x1488c01, 0xc000123ca0)
	/Users/remygreinhofer/go/src/github.com/cvbarros/go-teamcity-sdk/teamcity/build_type_test.go:261 +0x6e
github.com/cvbarros/go-teamcity-sdk/teamcity_test.createTestBuildType(0xc000125a00, 0x0, 0x14287b5, 0x14, 0x104c0ba)
	/Users/remygreinhofer/go/src/github.com/cvbarros/go-teamcity-sdk/teamcity/build_type_test.go:257 +0x63
github.com/cvbarros/go-teamcity-sdk/teamcity_test.TestAgentRequirement_Create(0xc000125a00)
	/Users/remygreinhofer/go/src/github.com/cvbarros/go-teamcity-sdk/teamcity/agent_requirement_test.go:14 +0x8a
testing.tRunner(0xc000125a00, 0x143d9d0)
	/usr/local/Cellar/go/1.11.5/libexec/src/testing/testing.go:827 +0xbf
created by testing.(*T).Run
	/usr/local/Cellar/go/1.11.5/libexec/src/testing/testing.go:878 +0x35c
FAIL	github.com/cvbarros/go-teamcity-sdk/teamcity	0.021s

I'm not sure wether it is a platform difference, or a go version problem.

$ go version
go version go1.11.5 darwin/amd64

EDIT
I ran the tests both from master and my branch and I got the same results.

[ss-remygreinhofer]

You can scratch the previous comment, I forgot to set the TEAMCITY_ADDR environment variable... Now all the tests are passing.

This led me to write a Makefile to simplify this type of tasks: PR #57 .

[ss-remygreinhofer]

@cvbarros I added some tests to ensure the new step can be created and added (I did the same thing you did for the PowerShell step) and I updated the setup to install the Octopus plugin automatically.

I did include PR #57 into this one as it seems clearer to me that way, but in case you reject it for some reason, I could figure out a way around it.

[cvbarros]

I've merged #57 first, sorry missed the comment. I think after a rebase this will be good to be merged!
How was it to add tests to the new structure? Any feedback?
Thanks!

[ss-remygreinhofer]

The branch is rebased.

Testify looks like a great framework, and the reference in the Go world for asserting and mocking, but my experience is too limited to provide you with valuable feedback. Besides I just mirrored what you did for the PowerShell step, so it was very straightforward.

Let me send you a few more PRs and I'll have an opinion 😉

[cvbarros]

Nice! Thanks a lot for the contribution, going to merge this.