Add unit tests with mocking

shared/src/commonMain/kotlin/com/tle/astrologylibrary/Subject.kt

@@ -0,0 +1,10 @@
+package com.tle.astrologylibrary
+
+@OpenForMokkery
+class A constructor()
+@OpenForMokkery
+class B constructor()
+class Subject(a: A, b: B) {
+    val a: A = a
+    val b: B = b
+}

shared/src/commonTest/kotlin/com/tle/astrologylibrary/SubjectTest.kt

@@ -0,0 +1,16 @@
+package com.tle.astrologylibrary
+
+import dev.mokkery.mock
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class SubjectTest {
+    @Test
+    fun testCreateSubject() {
+        val a = mock<A> {}
+        val b = mock<B> {}
+        val subject = Subject(a, b)
+        assertEquals(a, subject.a)
+        assertEquals(b, subject.b)
+    }
+}