Revert "Be more lenient about instantiation keys"

This reverts commit 3c24dbcd3dda62045bdc42965ded18c6bd3faead. I can't
figure out how to do the logic about replacing caps into
desired_capabilities before the object gets instantiated and we start
making errant requests out to the appium server.
Remove biased defaults during instantiation
v0.05

 - Restore restrictions about caps vs desired; this is just 0.03 again.
Update generated cpanfile and readme