Don't read library version from bundle. (#532)

It's not available when the library is used from another bundle.

Fixes #530.

Source/ARTDefault.m

@@ -13,8 +13,7 @@ @implementation ARTDefault
 NSString *const ARTDefault_restHost = @"rest.ably.io";
 NSString *const ARTDefault_realtimeHost = @"realtime.ably.io";
 NSString *const ARTDefault_version = @"0.8";
-NSString *const ARTDefault_ablyBundleId = @"io.ably.Ably";
-NSString *const ARTDefault_bundleVersionKey = @"CFBundleShortVersionString";
+NSString *const ARTDefault_libraryVersion = @"0.8.7";
 NSString *const ARTDefault_platform = @"ios-";
 
 static int _realtimeRequestTimeout = 10.0;
@@ -69,10 +68,7 @@ + (void)setConnectionStateTtl:(NSTimeInterval)value {
 }
 
 + (NSString *)libraryVersion {
-    NSBundle *ablyBundle = [NSBundle bundleWithIdentifier:ARTDefault_ablyBundleId];
-    NSDictionary *infoDictionary = [ablyBundle infoDictionary];
-    NSString *versionString = infoDictionary[ARTDefault_bundleVersionKey];
-    return [NSString stringWithFormat:@"%@%@", ARTDefault_platform, versionString];
+    return [NSString stringWithFormat:@"%@%@", ARTDefault_platform, ARTDefault_libraryVersion];
 }
 
 @end