Fix version calculation on non windows (#621)

+semver:patch

Author: hazzik

Diff for: build/version.cake

@@ -21,37 +21,34 @@ public class BuildVersion
         string informationalVersion = null;
         string milestone = null;
 
-        if (context.IsRunningOnWindows())
+        context.Information("Calculating Semantic Version");
+        if (!parameters.IsLocalBuild || parameters.IsPublishBuild || parameters.IsReleaseBuild)
         {
-            context.Information("Calculating Semantic Version");
-            if (!parameters.IsLocalBuild || parameters.IsPublishBuild || parameters.IsReleaseBuild)
-            {
-                context.GitVersion(new GitVersionSettings{
-                    UpdateAssemblyInfo = false,
-                    OutputType = GitVersionOutput.BuildServer
-                });
-
-                version = context.EnvironmentVariable("GitVersion_MajorMinorPatch");
-                semVersion = context.EnvironmentVariable("GitVersion_LegacySemVerPadded");
-                assemblyVersion = context.EnvironmentVariable("GitVersion_AssemblySemVer");
-                informationalVersion = context.EnvironmentVariable("GitVersion_InformationalVersion");
-                milestone = string.Concat("v", version);
-            }
-
-            GitVersion assertedVersions = context.GitVersion(new GitVersionSettings
-            {
-                OutputType = GitVersionOutput.Json,
+            context.GitVersion(new GitVersionSettings{
+                UpdateAssemblyInfo = false,
+                OutputType = GitVersionOutput.BuildServer
             });
 
-            version = assertedVersions.MajorMinorPatch;
-            semVersion = assertedVersions.LegacySemVerPadded;
-            assemblyVersion = assertedVersions.AssemblySemVer;
-            informationalVersion = assertedVersions.InformationalVersion;
+            version = context.EnvironmentVariable("GitVersion_MajorMinorPatch");
+            semVersion = context.EnvironmentVariable("GitVersion_LegacySemVerPadded");
+            assemblyVersion = context.EnvironmentVariable("GitVersion_AssemblySemVer");
+            informationalVersion = context.EnvironmentVariable("GitVersion_InformationalVersion");
             milestone = string.Concat("v", version);
-
-            context.Information("Calculated Semantic Version: {0}", semVersion);
         }
 
+        GitVersion assertedVersions = context.GitVersion(new GitVersionSettings
+        {
+            OutputType = GitVersionOutput.Json,
+        });
+
+        version = assertedVersions.MajorMinorPatch;
+        semVersion = assertedVersions.LegacySemVerPadded;
+        assemblyVersion = assertedVersions.AssemblySemVer;
+        informationalVersion = assertedVersions.InformationalVersion;
+        milestone = string.Concat("v", version);
+
+        context.Information("Calculated Semantic Version: {0}", semVersion);
+
         var appVersion = typeof(ICakeContext).Assembly.GetName().Version.ToString();
 
         return new BuildVersion