Attempt to further reduce test flakiness

This plugin suffers from a large amount of test flakiness in the travis
ci environment. This commit continues the attempts to reduce this flakiness,
starting with #263

Mostly, this is increasing timeouts to deal with sluggish build servers, but also
includes a fix to a Stud.try call which would not retry due to failure exceptions
not matching.

Author: robbavey

spec/filewatch/tailing_spec.rb

@@ -450,7 +450,7 @@ module FileWatch
             FileUtils.mv(file_path2, file_path3)
           end
           .then("wait") do
-            wait(4).for do
+            wait(8).for do
               listener1.lines.size == 32 && listener2.calls == [:delete] && listener3.calls == [:open, :accept, :timed_out]
             end.to eq(true), "listener1.lines != 32 or listener2.calls != [:delete] or listener3.calls != [:open, :accept, :timed_out]"
           end

spec/inputs/file_read_spec.rb

@@ -363,7 +363,7 @@ def wait_for_start_processing(run_thread, timeout: 1.0)
     end
   end
 
-  def wait_for_file_removal(path, timeout: 3 * interval)
+  def wait_for_file_removal(path, timeout: 5 * interval)
     wait(timeout).for { File.exist?(path) }.to be_falsey
   end
 end