fix regexp

Author: jacobp100

src/index.js

@@ -6,8 +6,8 @@ import devPropertiesWithoutUnitsRegExp from './devPropertiesWithoutUnitsRegExp'
 import TokenStream from './TokenStream'
 
 // Note if this is wrong, you'll need to change tokenTypes.js too
-const numberOrLengthRe = /^([+-]?(?:\d*\.)?\d+(?:[Ee][+-]?\d+)?)(?:px)?$/
-const numberOnlyRe = /^[+-]?(?:\d*\.\d*|[1-9]\d*)(?:[Ee][+-]?\d+)?$/
+const numberOrLengthRe = /^([+-]?(?:\d*\.)?\d+(?:e[+-]?\d+)?)(?:px)?$/i
+const numberOnlyRe = /^[+-]?(?:\d*\.\d*|[1-9]\d*)(?:e[+-]?\d+)?$/i
 const boolRe = /^true|false$/i
 const nullRe = /^null$/i
 const undefinedRe = /^undefined$/i