add TestHsMembership instance

src/test/java/net/hostsharing/hsadminng/hs/office/membership/TestHsMembership.java

@@ -0,0 +1,19 @@
+package net.hostsharing.hsadminng.hs.office.membership;
+
+import com.vladmihalcea.hibernate.type.range.Range;
+
+import java.time.LocalDate;
+import java.util.UUID;
+
+import static net.hostsharing.hsadminng.hs.office.partner.TestHsOfficePartner.testPartner;
+
+public class TestHsMembership {
+
+    public static final HsOfficeMembershipEntity testMembership =
+            HsOfficeMembershipEntity.builder()
+                    .uuid(UUID.randomUUID())
+                    .partner(testPartner)
+                    .memberNumber(300001)
+                    .validity(Range.closedInfinite(LocalDate.parse("2020-01-01")))
+                    .build();
+}