fix websocket provider basic auth handling

[chaseadam]

Description

Previous handling of basic authentication credentials created base64 buffer concatenated user/pass. Should be creating buffer of base64 encoded string.

url-parse used always includes .auth object which overrides header built using .username and .password. Switch to else if.

NOTE: Fix does not address the lack of testing around the URL.auth object

I was unable to test against the ethereum test network because I couldn't figure out how to load the module locally (I am brand new to node).

Type of change

• Bug fix

Checklist:

• I have selected the correct base branch.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no warnings.
• I have updated or added types for all modules I've changed
• Any dependent changes have been merged and published in downstream modules.
• I ran npm run test in the root folder with success and extended the tests if necessary.
• I ran npm run build in the root folder and tested it in the browser and with node.
• I ran npm run dtslint in the root folder and tested that all my types are correct
• I have tested my code on an ethereum test network.

[coveralls]

Coverage decreased (-0.08%) to 95.66% when pulling 0e95560 on chaseadam:1.0 into 9dfc93e on ethereum:1.0.

[coveralls]

Coverage decreased (-0.08%) to 95.616% when pulling 91637b2 on chaseadam:1.0 into 5dccc72 on ethereum:1.0.

[nivida]

Thanks! I'll merge this PR and will test the URL.auth object.