Fix regression for supporting the default location of the .bootstraprc

[AlexKVal]

Replaces and continues #142

I've untangled the lot of knots 😄

To facilitate review process I've committed (almost) each step.

I checked both examples with these commands:
general part:

rm -rf node_modules && npm i
cd examples/basic or examples/css-modules
rm -rf node_modules
npm run install-local
npm i

testing:

DEBUG=true npm run bs3
[bootstrap-loader]: bootstrap-loader is using config file at examples/basic/.bootstraprc-3-example 

DEBUG=true npm run bs4
[bootstrap-loader]: bootstrap-loader is using config file at examples/basic/.bootstraprc-4-example

DEBUG=TRUE npm run bs4:default:dev
[bootstrap-loader]: Using config file examples/basic/.bootstraprc 

DEBUG=true npm run bs:no-config
[bootstrap-loader]:  Using config file examples/basic/node_modules/bootstrap-loader/.bootstraprc-3-default

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This change is

[justin808]

Reviewed 7 of 11 files at r1.
Review status: 7 of 11 files reviewed at latest revision, 1 unresolved discussion.

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src/bootstrap.config.js, line 26 [r1] (raw file):

  if (!config) {
    throw new Error(`I cannot parse the config file at ${configFilePath}'`);

Do we need a try/catch block? I guess the strategy is just to let the error go to the top level.

this is the right error:
Config file cannot be parsed: ${configFilePath}'

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Comments from Reviewable

[justin808]

GREAT JOB @AlexKVal!

Just the one change to the message....

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Reviewed 4 of 11 files at r1.
Review status: all files reviewed at latest revision, 1 unresolved discussion.

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Comments from Reviewable