Accept scopes and multiple imports from jspm

[AngelMunoz]

Packages with multiple dependencies like lit are not automatically processed by jspm, jspm prefers to send a whole tree of imports which if we want to support it (we do) We need to change the way we handle the JSPM response. For example this what is delivered from Lit.

{
    "staticDeps": [
        "https://ga.jspm.io/npm:@lit/reactive-element@1.0.0-rc.3/css-tag.js",
        "https://ga.jspm.io/npm:@lit/reactive-element@1.0.0-rc.3/reactive-element.js",
        "https://ga.jspm.io/npm:lit-element@3.0.0-rc.4/lit-element.js",
        "https://ga.jspm.io/npm:lit-html@2.0.0-rc.5/lit-html.js",
        "https://ga.jspm.io/npm:lit@2.0.0/index.js"
    ],
    "dynamicDeps": [],
    "map": {
        "imports": {
            "lit": "https://ga.jspm.io/npm:lit@2.0.0/index.js"
        },
        "scopes": {
            "https://ga.jspm.io/": {
                "@lit/reactive-element": "https://ga.jspm.io/npm:@lit/reactive-element@1.0.0-rc.3/reactive-element.js",
                "lit-element/lit-element.js": "https://ga.jspm.io/npm:lit-element@3.0.0-rc.4/lit-element.js",
                "lit-html": "https://ga.jspm.io/npm:lit-html@2.0.0-rc.5/lit-html.js"
            }
        }
    }
}

currently we expect the import, but we're not handling the scopes, that or course makes the jspm imports to fail in the browser, skypack and presumaby the other cdns handle the imports by themselves (i.e they transform to full specifiers) so that's why we got caught by this with jspm

[AngelMunoz]

fixed in v0.5.0