Add includes for array search of substring

The proposed addition is includes.  It allows you to pass an array of strings to check against a string for a partial match.  It uses include internally.  

Initially I was concerned about the naming, however, I resolved this issue by auto-converting any string inputs into an array that gets searched on.  Therefore, any coders intending to use include and instead using includes will get the same output.  

This is a good addition to the library, because it deals with strings.  The closest thing to this is the _.contains function in underscore, however, that falls short because it requires an exact match.  

I added this because I often find myself doing this  

```
if(_.str.include(someParam, 'lead') || _.str.include(someParam, 'contact') || _.str.include(someParam, 'account')){ //do something 
}
```
which could be written as
```
if(_.str.includes(someParam, ['lead', 'contact', 'account'])){ 
      //do something
}
```

Alternative suggestions:

1) Change include to accept string or array inputs.  If array, iterate over array using some as done in my commit.