Rename timer `Setup` function to `Schedule`

This patch was motivated by my desire to fix a typo in the function
name. The noun "setup" is 1 word. The verb "set up" is 2 words. All
other member functions are verbs, so this one should be a verb too.
That means that the function should be called `SetUp`. During the
discussion that resulted from the rename, James Kuszmaul pointed out
that "setting up" a timer can be confusing. It implies that you can
only "set up" a timer once. But the intent is to let users set up
timers as many times as they like. So we decided on renaming the
function to `Schedule`. That conveys the purpose and intent better.

I took this opportunity to fix some other typos involving the verb
"set up".

Signed-off-by: Philipp Schrader <philipp.schrader@gmail.com>
Change-Id: I2f557d1f946960af82711f248820d5e2d385a5d3
diff --git a/aos/actions/action_test.cc b/aos/actions/action_test.cc
index e7a3c53..ea46ed8 100644
--- a/aos/actions/action_test.cc
+++ b/aos/actions/action_test.cc
@@ -107,7 +107,8 @@
 
   void RunAt(monotonic_clock::time_point exec_time, std::function<void()> fn) {
     TimerHandler *timer = test_event_loop_->AddTimer(fn);
-    test_event_loop_->OnRun([timer, exec_time]() { timer->Setup(exec_time); });
+    test_event_loop_->OnRun(
+        [timer, exec_time]() { timer->Schedule(exec_time); });
   }
 
   FlatbufferDetachedBuffer<Configuration> configuration_;