Fix safeSlugname regex /-([a-z])/g  => /-(a-zA-Z)/g

safeSlugname with regex /-([a-z])/g will pass error
    
example: give `angular-Uid` will cause error
   
So I change the regex to /-([a-zA-Z])/g, that's mean `angular-Uid` will pass success to `angularUid`
Merge pull request #33 from huei90/patch-1

Fix safeSlugname regex /-([a-z])/g  => /-(a-zA-Z)/g