Added KilopoundForceFeetPerDegrees variant to RotationalStiffness (#749)

* Added KilopoundForceFeetPerDegrees variant to RotationalStiffness, along with PoundForceFeetPerDegrees

* Updated abbreviations according to PR remarks

Author: dschuermans

Common/UnitDefinitions/RotationalStiffness.json

@@ -20,6 +20,30 @@
           "Abbreviations": [ "N·m/rad", "Nm/rad" ]
         }
       ]
+    },
+    {
+      "SingularName": "PoundForceFootPerDegrees",
+      "PluralName": "PoundForceFeetPerDegrees",
+      "FromUnitToBaseFunc": "x*77.6826",
+      "FromBaseToUnitFunc": "x/77.6826",
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": [ "lbf·ft/deg" ]
+        }
+      ]
+    },
+    {
+      "SingularName": "KilopoundForceFootPerDegrees",
+      "PluralName": "KilopoundForceFeetPerDegrees",
+      "FromUnitToBaseFunc": "x*77682.6",
+      "FromBaseToUnitFunc": "x/77682.6",
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": [ "kipf·ft/°", "kip·ft/°g", "k·ft/°", "kipf·ft/deg", "kip·ft/deg", "k·ft/deg" ]
+        }
+      ]
     }
   ]
 }

UnitsNet.Tests/CustomCode/RotationalStiffnessTests.cs

@@ -28,6 +28,8 @@ namespace UnitsNet.Tests.CustomCode
     public class RotationalStiffnessTests : RotationalStiffnessTestsBase
     {
         protected override double NewtonMetersPerRadianInOneNewtonMeterPerRadian => 1;
+        protected override double PoundForceFeetPerDegreesInOneNewtonMeterPerRadian => 0.0128729;
+        protected override double KilopoundForceFeetPerDegreesInOneNewtonMeterPerRadian => 0.0128729e-3;
         protected override double MeganewtonMetersPerRadianInOneNewtonMeterPerRadian => 1e-6;
         protected override double KilonewtonMetersPerRadianInOneNewtonMeterPerRadian => 1e-3;
     }