Does not strip comments from interpolated expressions

[a2937]

Comments are not removed from code that uses interpolated expressions.

For example if campers have a line of code like :

const v = /*a*/`/*b*/${/*c*/12}`; 

The expected output should be

const v = `/*b*/${12}`;

However we end up with the following

const v = `/*b*/${/*c*/12}`;

Copied from: jonschlinkert/strip-comments#54