servicex init cli command

[MattShirley]

Address #646 (phase 1)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.34%. Comparing base (54819a3) to head (d11fad3).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #686      +/-   ##
==========================================
+ Coverage   98.27%   98.34%   +0.07%     
==========================================
  Files          29       30       +1     
  Lines        2085     2181      +96     
==========================================
+ Hits         2049     2145      +96     
  Misses         36       36              

Flag	Coverage Δ
unittests	98.34% <100.00%> (+0.07%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[ponyisi]

Can you address the coverage issue?

[ponyisi]

A bit of documentation in the docs area would be very welcome, e.g. in connect_servicex.rst . Can we get the three listed sites (maybe four with Purdue) set up with standard profiles?