Remove manual node.js installation instructions

[Dan Scott]

* Evergreen master, 3.4.0
* Ubuntu 16.04

The current server installation docs tell you to install the latest LTS version of Node.js if you haven't installed the -developer extras from the Makefile.install.

However, the version of Node.js installed by Makefile.install may not match the latest LTS version (for example, for 3.4.0 the Makefile.install version is 8.11.4 whereas latest LTS is 12.13.0). This can result in unexpected results when installing node modules.

As we already have an automated method of installing a particular version of Node, we should remove these conflicting instructions.

There were also problems running the PhantomJS tests against the /web/js/ui/default/staff AngularJS files in 3.4.0, and this is apparently a known problem. So I've added a commit to remove the "npm run test" step for that portion of the install docs.

Branch can be found at https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/dbs/docs_remove_node_source

I believe it should be applied to master and 3.4.

[Galen Charlton (gmc)]

I've merged the first patch (remove the instructions to install the latest Node LTS) to master and rel_3_4. I've not merged the second patch, as the patches for bug 1845693 have taken care of the PhantomJS problem.

Thanks, Dan!