Fix check-coverage with custom options

[wbyoung]

Specifically, if the temp directory is configured, this needs to be configured on the NYC instance for both the command line action check-coverage as well as the --check-coverage flag passed when executing tests.

[coveralls]

Changes Unknown when pulling 40605d4 on wbyoung:fix-check-coverage into ** on istanbuljs:master**.

[bcoe]

@wbyoung looks quite reasonable to me 👍 thanks for the contribution.

[bcoe]

@wbyoung thanks for the contribution, hopefully the first of many; I'm hoping to have at least a candidate release out to the next tag today.

[wbyoung]

@bcoe awesome — thanks for merging & releasing quickly!

[bcoe]

@wbyoung would love your help testing both of your patches:

npm cache clear; npm i nyc@next

once we're happy with our smoke testing, I'll promote this to latest.

[wbyoung]

@bcoe it looks like you released already… I have two projects that are now failing after this release. See wbyoung/relateify#1 and wbyoung/babel-plugin-transform-postcss#3.

The output I get is:

/Users/wbyoung/Code/relateify/node_modules/nyc/node_modules/istanbul-lib-coverage/lib/file.js:253
        for (i = 0; i < retArray.length; i += 1) {
                                ^

TypeError: Cannot read property 'length' of undefined
    at /Users/wbyoung/Code/relateify/node_modules/nyc/node_modules/istanbul-lib-coverage/lib/file.js:253:33
    at Array.forEach (native)
    at FileCoverage.merge (/Users/wbyoung/Code/relateify/node_modules/nyc/node_modules/istanbul-lib-coverage/lib/file.js:249:26)
    at /Users/wbyoung/Code/relateify/node_modules/nyc/node_modules/istanbul-lib-coverage/lib/coverage-map.js:54:26
    at Array.forEach (native)
    at CoverageMap.merge (/Users/wbyoung/Code/relateify/node_modules/nyc/node_modules/istanbul-lib-coverage/lib/coverage-map.js:51:29)
    at /Users/wbyoung/Code/relateify/node_modules/nyc/index.js:432:9
    at Array.forEach (native)
    at NYC._getCoverageMapFromAllCoverageFiles (/Users/wbyoung/Code/relateify/node_modules/nyc/index.js:431:22)
    at NYC.checkCoverage (/Users/wbyoung/Code/relateify/node_modules/nyc/index.js:464:18)
npm ERR! Test failed.  See above for more details.

[bcoe]

try rm -rf ./node_modules/.cache, I don't think we've made any major changes to Istanbul-lib-coverage so this is weird.