Adding Codecov for Test Coverage to CircleCI yaml (getodk#1462)

* Adds codecov badge to README

* Modifies circle yaml

* Adds jacoco plugin

* Update README.md

README.md

@@ -2,6 +2,7 @@
 ![Platform](https://img.shields.io/badge/platform-Android-blue.svg)
 [![License](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
 [![Build status](https://circleci.com/gh/opendatakit/collect.svg?style=shield&circle-token=:circle-token)](https://circleci.com/gh/opendatakit/collect)
+[![codecov.io](https://codecov.io/github/opendatakit/collect/branch/master/graph/badge.svg)](https://codecov.io/github/opendatakit/collect)
 [![Slack status](http://slack.opendatakit.org/badge.svg)](http://slack.opendatakit.org)
 
 ODK Collect is an Android app for filling out forms. It is designed to be used in resource-constrained environments with challenges such as unreliable connectivity or power infrastructure. ODK Collect is part of Open Data Kit (ODK), a free and open-source set of tools which help organizations author, field, and manage mobile data collection solutions. Learn more about the Open Data Kit project and its history [here](https://opendatakit.org/about/) and read about example ODK deployments [here](https://opendatakit.org/about/deployments/).

build.gradle

@@ -5,6 +5,7 @@ buildscript {
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.dicedmelon.gradle:jacoco-android:0.1.1'
         classpath 'com.google.gms:google-services:3.0.0'
     }
 }

circle.yml

@@ -36,7 +36,7 @@ test:
         - ./gradlew findbugs -Pandroid.useDexArchive=false
         - ./gradlew lint -Pandroid.useDexArchive=false
         - ./gradlew checkstyle -Pandroid.useDexArchive=false
-        - ./gradlew testDebugUnitTest -Pandroid.useDexArchive=false
+        - ./gradlew build jacocoTestReport testDebugUnitTest -Pandroid.useDexArchive=false
 
         # Instrumented tests take time, so only run them on master
         # SD card needed for circleci-android22 image
@@ -65,3 +65,4 @@ test:
 
         - if [ $CIRCLE_BRANCH = 'master' ]; then cp -r collect_app/build/outputs/apk $CIRCLE_ARTIFACTS; fi
         - if [ $CIRCLE_BRANCH = 'master' ]; then cp -r collect_app/build/reports/androidTests/connected $CIRCLE_TEST_REPORTS/androidTests; fi
+        - bash <(curl -s https://codecov.io/bash)

collect_app/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'com.android.application'
+apply plugin: 'jacoco-android'
 apply from: '../config/quality.gradle'
 
 import com.android.ddmlib.DdmPreferences