Fix broken tests.

// FREEBIE

src/Account/TSAccountManager.h

@@ -84,6 +84,10 @@ extern NSString *const kNSNotificationName_LocalNumberDidChange;
 
 + (void)unregisterTextSecureWithSuccess:(void (^)())success failure:(void (^)(NSError *error))failureBlock;
 
+#ifdef DEBUG
+- (BOOL)isMockForTests;
+#endif
+
 @end
 
 NS_ASSUME_NONNULL_END

src/Account/TSAccountManager.m

@@ -42,7 +42,12 @@ NSString *const kNSNotificationName_LocalNumberDidChange = @"kNSNotificationName
     _networkManager = networkManager;
     _storageManager = storageManager;
 
-    OWSSingletonAssert();
+
+#ifdef DEBUG
+    if (![self isMockForTests]) {
+        OWSSingletonAssert();
+    }
+#endif
 
     return self;
 }
@@ -59,6 +64,13 @@ NSString *const kNSNotificationName_LocalNumberDidChange = @"kNSNotificationName
     return sharedInstance;
 }
 
+#ifdef DEBUG
+- (BOOL)isMockForTests
+{
+    return NO;
+}
+#endif
+
 - (void)setPhoneNumberAwaitingVerification:(NSString *_Nullable)phoneNumberAwaitingVerification
 {
     _phoneNumberAwaitingVerification = phoneNumberAwaitingVerification;

src/Network/API/TSNetworkManager.h

@@ -30,7 +30,7 @@ extern NSString *const TSNetworkManagerDomain;
 
 - (instancetype)init NS_UNAVAILABLE;
 
-+ (id)sharedManager;
++ (instancetype)sharedManager;
 
 - (void)makeRequest:(TSRequest *)request
             success:(void (^)(NSURLSessionDataTask *task, id responseObject))success

src/Network/API/TSNetworkManager.m

@@ -22,7 +22,8 @@ typedef void (^failureBlock)(NSURLSessionDataTask *task, NSError *error);
 
 #pragma mark Singleton implementation
 
-+ (id)sharedManager {
++ (instancetype)sharedManager
+{
     static TSNetworkManager *sharedMyManager = nil;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
@@ -31,7 +32,6 @@ typedef void (^failureBlock)(NSURLSessionDataTask *task, NSError *error);
     return sharedMyManager;
 }
 
-
 - (instancetype)initDefault
 {
     self = [super init];