Throw logical error message when no package.json is found locally

[dawsbot]

When there is no package.json locally:

Line 94 of package-tar.js should hold the answer. Check for existence of dependencies in the json object before accessing it.

---

$ instafork a

? Where do you want to get the source from? remote registry
remote registry

Stdout: a-2.1.0.tgz

Stdout:
/Users/dawsonbotsford/cli/instafork/dist/helpers/package-tar.js:149
var existingDeps = _readPkgUp2.default.sync({ cwd: process.cwd() }).pkg.dependencies;
^

TypeError: Cannot read property 'dependencies' of undefined
at packageTar.installDeps (/Users/dawsonbotsford/cli/instafork/dist/helpers/package-tar.js:149:78)
at /Users/dawsonbotsford/cli/instafork/dist/instafork.js:52:20
at /Users/dawsonbotsford/cli/instafork/dist/helpers/package-tar.js:117:9
at ChildProcess.exithandler (child_process.js:193:7)
at emitTwo (events.js:106:13)
at ChildProcess.emit (events.js:191:7)
at maybeClose (internal/child_process.js:852:16)
at Process.ChildProcess._handle.onexit (internal/child_process.js:215:5)

[dawsbot]

Closed with 8c50463baa4071b3bc6de91ec8c714e09eb350c5