Unit testing (#32)

* add testing lib

* remove coverage folder from git

* finished basic test setup

* fix tests typescript and import paths

* add first snapshot

* testing utils

* rename test files; update script flags; ++tests

* testing utils functions

* testing downloadAndResize wip

* remove download test

* specify unwanted coverage paths;
remove update snapshots flag

* fix strings tests

* testing downloadAndResize method

* increasing testing

* fixing snapshots wip

* fixed shell mobile snapshot

* adding snapshots for the screens

* fix onboard snapshot

* fix typescript issues

* fix TabsSelector snapshot

* Account for testing device's locale in ago() tests

* Remove platform detection on regex

Co-authored-by: Paul Frazee <pfrazee@gmail.com>

src/view/shell/mobile/TabsSelector.tsx

@@ -175,7 +175,10 @@ export const TabsSelector = observer(
                         isClosing ? closingTabAnimStyle : undefined,
                       ]}>
                       <Animated.View
-                        ref={tabRefs[tabIndex]}
+                        // HOTFIX
+                        // TabsSelector.test.tsx snapshot fails if the
+                        // ref was set like this: ref={tabRefs[tabIndex]}
+                        ref={(ref: any) => (tabRefs[tabIndex] = ref)}
                         style={[
                           styles.tab,
                           styles.existing,