Update dependencies

dependencies {

    implementation project(':cert4android')

    implementation 'io.reactivex:rxandroid:1.2.0'

    implementation 'io.reactivex:rxjava:1.1.5'

    implementation 'io.reactivex:rxandroid:1.2.1'

    implementation 'io.reactivex:rxjava:1.3.8'

    implementation 'com.yydcdut:markdown-processor:0.1.3'

    implementation 'com.yydcdut:rxmarkdown-wrapper:0.1.3'

import android.os.Bundle;

import android.text.SpannableString;

import android.text.TextUtils;

import androidx.annotation.Nullable;

import androidx.core.view.MenuItemCompat;

import androidx.appcompat.widget.ShareActionProvider;

import android.util.Log;

import android.view.Menu;

import android.view.MenuInflater;