Lock RNN to 7.0.0 (7.1.0 requires iOS 11)

Author: M-i-k-e-l

package.json

@@ -96,7 +96,7 @@
     "react-native": "0.63.2",
     "react-native-gesture-handler": "1.6.1",
     "react-native-keyboard-tracking-view": "^5.6.1",
-    "react-native-navigation": "^7.0.0",
+    "react-native-navigation": "7.0.0",
     "react-native-reanimated": "1.9.0",
     "react-test-renderer": "^16.13.1",
     "shell-utils": "^1.0.10",