Updaet readme for June release (microsoft#1684)

Merge branch 'master' into release/0.30

Add loading spinner component (microsoft#1580)

removed discontinued red bar from error detail (microsoft#1521)

Initial Profiler extension scaffolding (microsoft#1451)

* Copy agent to profiler extension

* A few mote edits

added register content method to dialog and tab (microsoft#1415)

* added register content method to dialog and tab

Bump SQL Ops to 0.29.3 (microsoft#1349)

Bump Tools Service to 1.4.0-alpha.30 (microsoft#1337)

Update SQL Tools to 1.4.0-alpha.25 (microsoft#1304)

Bump SQL Ops Studio to 0.28.6 (microsoft#1252)