Use the same version of nunit console runner that appveyor does (3.7)

Author: shana

test/GitHub.InlineReviews.UnitTests/packages.config

@@ -10,7 +10,7 @@
   <package id="Microsoft.Win32.Primitives" version="4.0.1" targetFramework="net461" />
   <package id="NSubstitute" version="2.0.3" targetFramework="net461" />
   <package id="NUnit" version="3.9.0" targetFramework="net461" />
-  <package id="NUnit.ConsoleRunner" version="3.8.0" targetFramework="net461" />
+  <package id="NUnit.ConsoleRunner" version="3.7.0" targetFramework="net461" />
   <package id="NUnit3TestAdapter" version="3.9.0" targetFramework="net461" />
   <package id="Rx-Core" version="2.2.5-custom" targetFramework="net461" />
   <package id="Rx-Interfaces" version="2.2.5-custom" targetFramework="net461" />

test/GitHub.UI.UnitTests/packages.config

@@ -2,7 +2,7 @@
 <packages>
   <package id="NSubstitute" version="2.0.3" targetFramework="net461" />
   <package id="NUnit" version="3.9.0" targetFramework="net461" />
-  <package id="NUnit.ConsoleRunner" version="3.8.0" targetFramework="net461" />
+  <package id="NUnit.ConsoleRunner" version="3.7.0" targetFramework="net461" />
   <package id="NUnit3TestAdapter" version="3.9.0" targetFramework="net461" />
   <package id="Serilog" version="2.5.0" targetFramework="net461" />
   <package id="Serilog.Enrichers.Thread" version="3.0.0" targetFramework="net461" />

test/TrackingCollectionTests/packages.config

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="NUnit" version="3.9.0" targetFramework="net461" />
-  <package id="NUnit.ConsoleRunner" version="3.8.0" targetFramework="net461" />
+  <package id="NUnit.ConsoleRunner" version="3.7.0" targetFramework="net461" />
   <package id="NUnit3TestAdapter" version="3.9.0" targetFramework="net461" />
   <package id="Rx-Core" version="2.2.5-custom" targetFramework="net452" />
   <package id="Rx-Interfaces" version="2.2.5-custom" targetFramework="net452" />

test/UnitTests/packages.config

@@ -26,7 +26,7 @@
   <package id="Microsoft.VisualStudio.TextManager.Interop.8.0" version="8.0.50727" targetFramework="net461" />
   <package id="NSubstitute" version="2.0.3" targetFramework="net461" />
   <package id="NUnit" version="3.9.0" targetFramework="net461" />
-  <package id="NUnit.ConsoleRunner" version="3.8.0" targetFramework="net461" />
+  <package id="NUnit.ConsoleRunner" version="3.7.0" targetFramework="net461" />
   <package id="NUnit3TestAdapter" version="3.9.0" targetFramework="net461" />
   <package id="Rothko" version="0.0.3-ghfvs" targetFramework="net461" />
   <package id="Rx-Core" version="2.2.5-custom" targetFramework="net45" />