Introduce Codecov to get Coverage results, see #3666

Author: Vogel612

appveyor.yml

@@ -33,7 +33,6 @@ platform: Any CPU
 cache:
   - packages/ -> **/packages.config
 
-
 install:
   set PATH=C:\Program Files (x86)\MSBuild\15.0\Bin;%PATH%
 assembly_info:
@@ -42,7 +41,10 @@ assembly_info:
   assembly_version: '{version}'
 
 before_build:
-  cinst innosetup
+  - cinst innosetup
+  - cinst codecov
+  - cinst opencover.portable
+  - nuget restore
 build:
   verbosity: minimal
 

codecov.yml

@@ -0,0 +1,12 @@
+codecov:
+  branch:
+    - next
+    - master
+  ci:
+    - appveyor
+  max_report_age: off
+    
+coverage:
+  round: nearest
+  precision: 2
+  range: 40..80