Web applications built using e.g. angular2, usually requires that the
packages in devDependencies are available.
Thus, add an option '--fetch-dev' to both devtool add and recipetool, to
add npm packages in devDependencies to DEPENDS.
(From OE-Core rev: f246f820d53b459596fde6758a09f7a0d7db7c4c)
Signed-off-by: Anders Darander <anders@chargestorm.se>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>