ci: add wheel dependency to imgtool publishing

Should fix the current fail trying to build a bdist_wheel.

Signed-off-by: Fabio Utzig <[email protected]>

Author: utzig

ci/imgtool_install.sh

@@ -19,5 +19,5 @@ if [[ $TRAVIS == "true" ]]; then
     fi
 fi
 
-pip3 install setuptools twine packaging
+pip3 install setuptools twine packaging wheel
 pip3 install --pre imgtool --no-binary :all: