add prettier task for standardized code formatting => easier cross-branch/fork code comparison and merging

[GerHobbelt]

• add prettier task for standardized code formatting => easier cross-branch/fork code comparison and merging.
• npm run prettier

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You can also cherry-pick the essential package.json edit at commit
SHA-1: 87dc0a6
plus the line-width tweak at commit
SHA-1: 39b004d * fiddling a little with prettier line width: 80 --> 120, so we get fewer lines/edits compared to vanilla mainstream.

The rest of the patch is the result of npm run prettier...

Alternatively, the entire thing is squashed in SHA-1: f446e71

• add prettier task for standardized code formatting => easier cross-branch/fork code comparison and merging.
• npm run prettier

[coveralls]

Pull Request Test Coverage Report for Build 575

• 86 of 107(80.37%) changed or added relevant lines in 11 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.02%) to 88.713%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
lib/read-wasm.js	0	1	0.0%
lib/source-map-generator.js	10	11	90.91%
lib/util.js	4	5	80.0%
lib/source-map-consumer.js	48	50	96.0%
lib/wasm.js	6	22	27.27%

Files with Coverage Reduction	New Missed Lines	%
lib/util.js	1	79.45%

Totals
Change from base Build 572:	0.02%
Covered Lines:	2481
Relevant Lines:	2733

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💛 - Coveralls

[jasonLaster]

Thanks @GerHobbelt! And so, sorry for the delay.

It looks npm run lint finds a couple of issues with concatenation, which could probably be fixed with string templates.

/Users/jlaster/src/moz/source-map/test/test-source-map-consumer.js
1421:72 error Unexpected string concatenation of literals no-useless-concat
/Users/jlaster/src/moz/source-map/test/test-source-map-generator.js
822:60 error Unexpected string concatenation of literals no-useless-concat
/Users/jlaster/src/moz/source-map/test/util.js
29:71 error Unexpected string concatenation of literals no-useless-concat
109:58 error Unexpected string concatenation of literals no-useless-concat
109:84 error Unexpected string concatenation of literals no-useless-concat
124:56 error Unexpected string concatenation of literals no-useless-concat
124:79 error Unexpected string concatenation of literals no-useless-concat
145:58 error Unexpected string concatenation of literals no-useless-concat
145:84 error Unexpected string concatenation of literals no-useless-concat
160:56 error Unexpected string concatenation of literals no-useless-concat
160:79 error Unexpected string concatenation of literals no-useless-concat
181:58 error Unexpected string concatenation of literals no-useless-concat
181:84 error Unexpected string concatenation of literals no-useless-concat
198:56 error Unexpected string concatenation of literals no-useless-concat
198:79 error Unexpected string concatenation of literals no-useless-concat
213:37 error Unexpected string concatenation of literals no-useless-concat
213:63 error Unexpected string concatenation of literals no-useless-concat
214:35 error Unexpected string concatenation of literals no-useless-concat
214:58 error Unexpected string concatenation of literals no-useless-concat
225:37 error Unexpected string concatenation of literals no-useless-concat
225:63 error Unexpected string concatenation of literals no-useless-concat
226:35 error Unexpected string concatenation of literals no-useless-concat
226:58 error Unexpected string concatenation of literals no-useless-concat

Once this is rebased and green I'll happily merge.

[jasonLaster]

I pushed some tweaks that

1. add eslint prettier integration so that npm run lint catches issues
2. re-runs npm run lint on the project to catch issues prettier introduced
3. add npm run lint to the travis.yml