Removed InvariantCulture

Removed `InvariantCulture` on the following `UnitSystemTests` tests:
	1. `NegativeInfinityFormatting`
	2. `PositiveInfinityFormatting`

Author: gojanpaolo

UnitsNet.Tests/UnitSystemTests.cs

@@ -444,7 +444,7 @@ public void MapUnitToAbbreviation_AddCustomUnit_DoesNotOverrideDefaultAbbreviati
         [Fact]
         public void NegativeInfinityFormatting()
         {
-            Assert.Equal("-∞ m", Length.FromMeters(double.NegativeInfinity).ToString(LengthUnit.Meter, CultureInfo.InvariantCulture));
+            Assert.Equal("-∞ m", Length.FromMeters(double.NegativeInfinity).ToString());
         }
 
         [Fact]
@@ -476,7 +476,7 @@ public void Parse_UnambiguousUnitsDoesNotThrow()
         [Fact]
         public void PositiveInfinityFormatting()
         {
-            Assert.Equal("∞ m", Length.FromMeters(double.PositiveInfinity).ToString(LengthUnit.Meter, CultureInfo.InvariantCulture));
+            Assert.Equal("∞ m", Length.FromMeters(double.PositiveInfinity).ToString());
         }
 
         /// <summary>