Bulk converted assert => unexpected.

Ran these commands and fixed the rest by hand:

perl -pi -e "s/assert = require\('assert'\),/expect = require('.\/unexpected-with-plugins'),/g;" *-test.js
perl -pi -e "s/assert\.equal\(assetGraph\.findAssets\(/expect(assetGraph, 'to contain assets', /g;" *-test.js
perl -pi -e "s/assert\.equal\(assetGraph\.findRelations\(/expect(assetGraph, 'to contain relations', /g;" *-test.js
perl -pi -e "s/assert\.equal\((.*)\.length, (\d+)\);/expect(\$1, 'to have length', \$2);/g;" *-test.js
perl -pi -e "s/(expect\(assetGraph,.*)\).length(, \d+\);)/\$1\$2/g;" *-test.js
perl -pi -e "s/assert\.matches\((.*), (\/.*?\/)\);/expect(\$1, 'to match', \$2);/g;" *-test.js
perl -pi -e "s/(expect\(assetGraph, 'to contain assets', )\{type: ('[^']*')\}/\$1\$2/g;" *-test.js
perl -pi -e "s/(expect\(assetGraph, 'to contain (?:asset|relation))s'(,.*?), 1\);/\$1'\$2);/g;" *-test.js
perl -pi -e "s/(expect\(assetGraph, 'to contain (?:asset|relation)s?)', ,/\$1',/g;" *-test.js
perl -pi -e "s/(expect\(assetGraph, 'to contain )((?:asset|relation)s?'.*?), 0\);/\$1no \$2);',/g;" *-test.js
perl -pi -e "s/(expect\(assetGraph, 'to contain (?:asset|relation)s?', )\{type: ('[^']*')\}/\$1\$2/g;" *-test.js
perl -pi -e "s/(expect\(assetGraph, 'to contain (?:asset|relation)'), \);/\$1);/g;" *-test.js
perl -pi -e "s/(expect\(.*?'to contain no (?:asset|relation)s'.*?\);)',/\$1/g;" test/*-test.js
perl -pi -e "s/assert\.equal\(([^,]+), ('[^']*')\);/expect(\$1, 'to equal', \$2);/g;" test/*.js
perl -pi -e "s/assert\.isNotNull\(([^,]+)\);/expect(\$1, 'not to be null');/g;" test/*.js
perl -pi -e "s/assert\.isNull\(([^,]+)\);/expect(\$1, 'to be null');/g;" test/*.js
perl -pi -e "s/assert\.equal\(([^,]+),$/expect(\$1, 'to equal',/g;" test/*.js
perl -pi -e "s/assert\.instanceOf\(([^,]+),/expect(\$1, 'to be an',/g;" test/*.js
perl -pi -e "s/assert\.isFalse\((.*?)\);/expect(\$1, 'to be false');/g;" test/*.js
perl -pi -e "s/assert\.equal\((.*?)\.indexOf\(('[^']*')\), -1\);/expect(\$1, 'not to contain', \$2);/g;" test/*.js
perl -pi -e "s/assert\.notEqual\((.*?)\.indexOf\(('[^']*')\), -1\);/expect(\$1, 'to contain', \$2);/g;" test/*.js
perl -pi -e "s/assert\.isObject\((.*)\);/expect(\$1, 'to be an object');/g;" test/*.js
perl -pi -e "s/assert\.isArray\((.*)\);/expect(\$1, 'to be an array');/g;" test/*.js
perl -pi -e "s/assert\.equal\((.*), ([^,]+)\);/expect(\$1, 'to equal', \$2);/g;" test/*.js
perl -pi -e "s/assert\.deepEqual\((.*),$/expect(\$1, 'to equal',/g;" test/*.js
perl -pi -e "s/assert\.ok\((.*)\);/expect(\$1, 'to be ok');/" test/*.js
perl -pi -e "s/assert\.deepEqual\((.*), \[$/expect(\$1, 'to equal', \[/g;" test/*.js
perl -pi -e "s/assert\.deepEqual\((.*), (\[[^\]]*\])\);$/expect(\$1, 'to equal', \$2);/g;" test/*.js
perl -pi -e "s/assert\.match\((.*),$/expect(\$1, 'to match',/g;" test/*.js
perl -pi -e "s/assert\.matches\((.*),$/expect(\$1, 'to match',/g;" test/*.js
perl -pi -e "s/assert\.matches\((.*), (.*)\);?$/expect(\$1, 'to match', \$2);/g;" test/*.js
perl -pi -e "s/expect\(assetGraph\.findRelations\((.*?), true\), 'to have length', (\d+)\);/expect(assetGraph, 'to contain relations including unresolved', \$1, \$2);/g" test/*.js
perl -pi -e "s/(expect\(assetGraph, 'to contain relations including unresolved', )\{type: ('[^']*')\}/\$1\$2/g;" test/*.js
perl -pi -e "s/(expect\(assetGraph, 'to contain relations)(', .*?), true(, \d+\);)/\$1 including unresolved\$2\$3/g;" test/*.js
perl -pi -e 's/\.run\(this\.callback\)/.run(done)/g' *-test.js
Converted compileCoffeeScriptToJavaScript test to mocha.
Converted compileStylusToCss test to mocha.
Converted compileLessToCss test to mocha.
Converted compressJavaScript test to mocha.
Converted convertCssImportsToHtmlStyles test to mocha.
Converted convertHtmlRequireJsMainToHtmlScript test to mocha.
Converted convertStylesheetsToInlineStyles test to mocha.
Converted CssAlphaImageLoader test to mocha.
Converted CssBehavior test to mocha.
Converted CssFontFaceSrc test to mocha.
Converted CssImage test to mocha.
Converted CssImport test to mocha.
Converted CssMediaRule test to mocha and merged it into the CssImage test.
Converted Css test to mocha.
Converted file: test to mocha.
Converted data: test to mocha.
Converted externalizeAndMergeIdenticalAssets test to mocha.
Converted findAssets test to mocha.