Added keymaps to help strings of rspec-mode, et. al

I don't use ruby and rspec-mode much and I can't remember the keymaps so I added them to the documentation strings.
You might not like my changes.  There is some magic I don't understand with \{foo-mode-map}.  The keymap appears that it must be named foo-mode-keymap for the magic to work.  \{foo-mode-map} gives me the complete path to each function whereas \{foo-mode-keymap} only gives me the last key stroke.
In any case, to make the magic work, I had to change rspec-mode-verifiable-keymap to rspec-verifiable-mode-keymap because the mode is rspec-verifiable-mode -- not rspec-mode-verifiable.