Make package executeable

[christian-bromann]

Rather than calling jscodeshift directly, e.g.:

$ npx jscodeshift -t ./node_modules/@wdio/codemod/protractor ./e2e/

It would be nicer to have a binary exposed that allows us to be more flexible with the codemod execution, e.g. to migrate from v5 to v7 it would be great to just having to call:

$ npx codemod v6 v7

which then calls jscodeshift seperately.

Also the package should automatically detect the files and pick e.g. TypeScript as parser if all files are written that way.

[christian-bromann]

In the MoT meetup today someone suggested to make this part of the schematic to allow things like:

$ ng e2e migrate ./specs/**.spec.js