update set_wait / no_wait logic

[bootstraponline]

the complex set_wait logic around implicit wait duplicates the api that already exists in the selenium webdriver gem. It should be removed.

[bootstraponline]

Also the default wait logic implicit_wait = @default_wait is unnecessary and should probably be removed. A default of 0 is preferred for an implicit wait to prevent conflicts with the explicit wait.

[tmulry]

set_wait should be removed from the readme as well. using default_wait= is the only way I could get appium to change the global wait time

[KazuCocoa]

example

KazuCocoa@ea06bdc