Add install target

[carolynvs]

The install target dumps the bin into ~/.porter and symlinks it to /usr/local/bin.

Note that this doesn't work with porter until #139 is merged.

[vdice]

As mentioned in #134 , shall we also install mixins to $(HOME)/.porter?

Also, thoughts on bubbling up actual install location ($(HOME)/.porter) as a top-level/re-usable $PORTER_HOME variable?

[carolynvs]

The install target runs build first, which is handling getting all of the mixins into bin before we dump the entire thing over to ~/.porter.

Here's what's in ~/.porter after I deleted my bin, and ~/.porter and then ran make install:

/Users/carolynvs/.porter
├── mixins
│   ├── azure
│   │   ├── azure
│   │   └── azure-runtime
│   ├── exec
│   │   ├── exec
│   │   └── exec-runtime
│   ├── helm
│   │   ├── helm
│   │   └── helm-runtime
│   └── porter
│       ├── porter
│       └── porter-runtime
├── porter
└── templates
    ├── porter.yaml
    └── run

Do you see anything missing?

Yeah, I originally expected that PORTER_HOME at the top of the Makefile would point to ~/.porter, then realized that it doesn't due to the CI tests. 😀 I will follow-up in another PR to change that so that it works like the other Makefiles (and still runs the CI tests from inside bin instead of against the system) #141.

[vdice]

Ah, now I gotcha 👍. Thank you for the detailed explanation.