Fix IDs (#1016)

* Allow any String IDs as long as they're sortable

* Allow any String IDs as long as they're sortable

app/src/test/java/com/keylesspalace/tusky/StringUtilsTest.kt

@@ -0,0 +1,34 @@
+package com.keylesspalace.tusky
+
+import com.keylesspalace.tusky.util.dec
+import com.keylesspalace.tusky.util.isLessThan
+import org.junit.Assert.*
+import org.junit.Test
+
+class StringUtilsTest {
+    @Test
+    fun isLessThan() {
+        val lessList = listOf(
+                "abc" to "bcd",
+                "ab" to "abc",
+                "cb" to "abc"
+        )
+        lessList.forEach { (l, r) -> assertTrue("$l < $r", l.isLessThan(r)) }
+        val notLessList = lessList.map { (l, r) -> r to l } + listOf(
+                "abc" to "abc"
+        )
+        notLessList.forEach { (l, r) -> assertFalse("not $l < $r", l.isLessThan(r)) }
+    }
+
+    @Test
+    fun dec() {
+        listOf(
+                "123" to "122",
+                "12B" to "12A",
+                "120" to "11z",
+                "100" to "zz",
+                "0" to "",
+                "" to ""
+        ).forEach { (l, r) -> assertEquals("$l - 1 = $r", r, l.dec()) }
+    }
+}

app/src/test/java/com/keylesspalace/tusky/TimelineFragmentTest.kt

@@ -1,2 +0,0 @@
-package com.keylesspalace.tusky
-