test: Basic unit testing of node package

[orpheuslummis]

RELEVANT ISSUE(S)

Resolves #502

DESCRIPTION

Provide basic unit tests for the node package.

HOW HAS THIS BEEN TESTED?

These are unit tests.

CHECKLIST:

• I have commented the code, particularly in hard-to-understand areas.
• I have made corresponding changes to the repo-held documentation.
• I have made sure that the PR title adheres to the conventional commit style (subset of the ones we use can be found under: tools/configs/chglog/config.yml

ENVIRONMENT / OS THIS WAS TESTED ON?

Please specify which of the following was this tested on (remove or add your own):

• Arch Linux
• Debian Linux
• MacOS
• Windows

[orpheuslummis]

You're invited to suggest further unit tests. Some of it isn't tested because it is expected to change relatively soon, such as key management, and others because I've found them difficult to test and just wanted a quick PR... e.g. validity of pubsub or Node.Boostrap or Node.Close .

[codecov]

Codecov Report

Merging #503 (2462418) into develop (45978e0) will decrease coverage by 12.62%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##           develop     #503       +/-   ##
============================================
- Coverage    65.09%   52.46%   -12.63%     
============================================
  Files           87       97       +10     
  Lines        10242    13144     +2902     
============================================
+ Hits          6667     6896      +229     
- Misses        2927     5574     +2647     
- Partials       648      674       +26     

Impacted Files	Coverage Δ
net/pb/net.pb.go	0.81% <0.00%> (ø)
net/server.go	13.98% <0.00%> (ø)
net/dialer.go	3.12% <0.00%> (ø)
net/client.go	0.00% <0.00%> (ø)
node/options.go	52.83% <0.00%> (ø)
net/dag.go	5.33% <0.00%> (ø)
net/pb/custom.go	0.00% <0.00%> (ø)
net/process.go	0.00% <0.00%> (ø)
net/peer.go	12.54% <0.00%> (ø)
node/node.go	66.12% <0.00%> (ø)
... and 3 more

[jsimnz]

Looking great

[jsimnz]

Last two items. LGTM