adds semver to dependencies

config-defs.js requires semver but the module is not in the deps.
This is probably not an issue with the way npm uses it but it's
causing a problem when using npmconf and npm-registry-client
separately. Added the same version used by npm-registry-client.
v0.0.20
Added missing ini dependency
v0.0.21
Adding bin-links

Adding "bin-links" option to support isaacs/npm#3090.
Setting it to false will prevent npm from making any symlinks to
binaries when using the "npm install" or "npm link" commands.
v0.0.22
cache-min: Default to 10s
v0.0.23
shorter shorthand for --no-registry
v0.0.24
Add 'shrinkwrap' Boolean config
v0.0.25
Add GlobalSign Organization CA

So that we can, one day, use the same cert for both the website
and the registry.
v0.1.0
use semver 2
v0.1.1
inherits@2
v0.1.2
Added tap to devDependencies so npm i/npm test works
v0.1.3