title: How to expand ggplot y axis limits to include maximum value
body: <p>Often in plots the Y axis value label is chopped off below the max value being plotted.  </p>
  
  <pre><code>For example:
  
  library(tidyverse)
  mtcars %&gt;% ggplot(aes(x=mpg, y = hp))+geom_point()
  </code></pre>
  
  <p>I know of scale_y_continous - but I can't figure out a smart way to do this.  Maybe I'm just overthinking things.    I don't wish to mess up the 'smart' breaks that are generated automatically.     </p>
  
  <p>I might try to go about this manually...</p>
  
  <pre><code>  mtcars  %&gt;% ggplot(aes(x=mpg, y=hp, color=as.factor(carb)))+geom_point()  + scale_y_continuous(limits = c(0,375))
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/wQ3id.png" rel="noreferrer"><img src="https://i.stack.imgur.com/wQ3id.png" alt="enter image description here"></a></p>
  
  <p>But this doesn't work like I mentioned above because of the 'smart breaks'.  Is there anyway for me to extend the default break interval to 1 more, so that in this case it would be 400?  Of course I would want this to be flexible for whatever dataset I am working with.  </p>