Import PyScript Version into Python Runtime (#958)

* Import current version as PyScript.__version__ and PyScript.version_info

* Add integration, python unit tests
 
* Mock pyscript.py with __mocks__/pyscript.js to make jest tests happy

pyscriptjs/jest.config.js

@@ -17,6 +17,7 @@ module.exports = {
         url: 'http://localhost',
     },
     moduleNameMapper: {
+        '^.*?pyscript\.py$': '<rootDir>/__mocks__/_pyscript.js',
         '^[./a-zA-Z0-9$_-]+\\.py$': '<rootDir>/__mocks__/fileMock.js',
         '\\.(css)$': '<rootDir>/__mocks__/cssMock.js',
     },