2.0.0

• (breaking) Drop java 7 support
• (breaking) Drop gradle 4 support
• Add python.usePipCache option to be able to disable cache for dependencies installation
  (--no-cache-dir)
  Also, option added to Pip object constructor and BasePipTask (with default from extension)
• Add Python.getBinaryDir() returning (in most cases) executed python binary folder
  (based on sys.executable with fallback to sys.prefix/bin)
• Fix virtualenv installation fail when "global" python is already virtualenv due to --user flag usage
  (like on travis now)
  • Add Python.isVirtualenv() method. Virtualenv is detected by activate script in python binary
    (which may not be always accurate, but should work in the majority of cases)
  • Pip internally use Python.isVirtualenv() to prevent applying --user flag
  • Configured (envPath) or created virtualenv is validated (shows error on incorrect configuration)
  • Show warnings for cases when virtualenv is created from another virtualenv (because it may have side effects)
• Add python extra args support (in contrast to extra agrs, applied after command, python args applied before):
  • Add Python.pythonArgs - args applied just after python executable
  • Add PythonTask.pythonArgs
• Add Virtualenv.python accessor to be able to configure additional arguments
• Add installed virtualenv version configuration: python.virtualenvVersion. This way, plugin will
  always install only known to be working version and avoid side effects of "just released"
  versions. By default, 16.7.9 would be installed because 20.0.x has some not fixed regressions
• Use gradle tasks configuration avoidance for lazy tasks initialization (no init when tasks not needed)