User endpoints fixes (#42)

src/endpoints/user.js

         const allUsers = await User.find({})
         return res.status(200).send(allUsers)
     } catch (e) {
-        next(e)
+        return res.status(500).send('Internal server error!')
     }
 }
 
             return res.status(404).send("User with the id of: " + id + " doesnt exist")
         }
 
-        return res.status(200).json(user)
+        return res.json(user)
     } catch (e) {
-        next(e)
+        return res.status(404).send('User not found!')
     }
 }
 
 
         return res.status(200).send('User updated successfully')
     } catch (e) {
-        next(e)
+        return res.status(500).send(e.message)
     }
 }
 
         }
         return res.status(200).send('user contacts updated successfully')
     } catch (e) {
-        next(e)
+        return res.status(500).send(e.message)
     }
 }
 
 
         return res.status(204).send('Deleting user with id of ' + id)
     } catch (e) {
-        next(e)
+        return res.status(500).send(e.message)
     }
 }