package – update css-compile script to use --math

--strict-math has been deprecated and replaced by --math.  See less/less.js#3274

package.json

@@ -29,7 +29,7 @@
 		"test": "echo \"Error: no test specified\" && exit 1",
 		"build": "npm run lint && npm run css",
 		"css": "npm run css-compile && npm run css-prefix && npm run css-minify",
-		"css-compile": "lessc --strict-math=on --source-map less/bootstrap.less dist/css/bootstrap.css && lessc --strict-math=on --source-map less/bootstrap-grid.less dist/css/bootstrap-grid.css && lessc --strict-math=on --source-map less/bootstrap-reboot.less dist/css/bootstrap-reboot.css",
+		"css-compile": "lessc --math=parens --source-map less/bootstrap.less dist/css/bootstrap.css && lessc --math=parens --source-map less/bootstrap-grid.less dist/css/bootstrap-grid.css && lessc --math=parens --source-map less/bootstrap-reboot.less dist/css/bootstrap-reboot.css",
 		"css-prefix": "postcss --config build/postcss.config.js --replace \"dist/css/*.css\"",
 		"css-minify": "cleancss --level 1 --format keep-breaks --source-map --source-map-inline-sources --output dist/css/bootstrap.min.css dist/css/bootstrap.css && cleancss --level 1 --format keep-breaks --source-map --source-map-inline-sources --output dist/css/bootstrap-grid.min.css dist/css/bootstrap-grid.css && cleancss --level 1 --format keep-breaks --source-map --source-map-inline-sources --output dist/css/bootstrap-reboot.min.css dist/css/bootstrap-reboot.css",
 		"lint": "eslint ."