Scientific notation should be supported for numbers/percentages/dimensions

[ThomasBrierley]

Input

foo {
  a: 1e1px;
  b: 1e-1px;
}

LibSass 3.5.0-beta.2

Error: Incompatible units: 'px' and 'e'.
        on line 3 of test.scss
>>   b: 1e-1px;

Sass 3.5.1 (Bleeding Edge)

foo {
  a: 1e1px;
  b: 1e-1px; }

Version info

$ node-sass --version
node-sass       4.5.3   (Wrapper)       [JavaScript]
libsass         3.5.0.beta.2    (Sass Compiler) [C/C++]

Spec sass/sass-spec#1163

[nschonni]

https://www.w3.org/TR/2014/CR-css-syntax-3-20140220/

Ruby Sass outpust both correctly in 3.5 and 4.0, but libsass has trouble with the negative version only
https://www.sassmeister.com/gist/bd4d877039b787fa24e35470eaa9c120

[xzyfer]

Thanks for confirming this issue @nschonni. I've added the spec.