Here is the complete POM.XML with latest dependencies.

http://maven.apache.org/xsd/maven-4.0.0.xsd"> 4.0.0

<groupId>com.student.app</groupId>
<artifactId>PaypalExmaples</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>PaypalExmaples</name>
<url>http://maven.apache.org</url>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>

    <!-- https://mvnrepository.com/artifact/io.rest-assured/rest-assured -->
    <dependency>
        <groupId>io.rest-assured</groupId>
        <artifactId>rest-assured</artifactId>
        <version>4.1.2</version>
        <scope>test</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.testng/testng -->
    <dependency>
        <groupId>org.testng</groupId>
        <artifactId>testng</artifactId>
        <version>7.1.0</version>
        <scope>test</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.hamcrest/hamcrest-all -->
    <dependency>
        <groupId>org.hamcrest</groupId>
        <artifactId>hamcrest-all</artifactId>
        <version>1.3</version>
        <scope>test</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.codehaus.groovy/groovy -->
    <dependency>
        <groupId>org.codehaus.groovy</groupId>
        <artifactId>groovy</artifactId>
        <version>2.5.9</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.11</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpmime -->
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpmime</artifactId>
        <version>4.3.1</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.9</version>
    </dependency>

    <dependency>
        <groupId>io.rest-assured</groupId>
        <artifactId>rest-assured-all</artifactId>
        <version>4.0.0</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.10.2</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.codehaus.groovy/groovy-all -->
    <dependency>
        <groupId>org.codehaus.groovy</groupId>
        <artifactId>groovy-all</artifactId>
        <version>2.5.9</version>
        <type>pom</type>
    </dependency>

    <dependency>
        <groupId>org.skyscreamer</groupId>
        <artifactId>jsonassert</artifactId>
        <version>1.5.0</version>
        <scope>test</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/commons-io/commons-io -->
    <dependency>
        <groupId>commons-io</groupId>
        <artifactId>commons-io</artifactId>
        <version>2.6</version>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.10.0.pr2</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.scribe/scribe -->
    <dependency>
        <groupId>org.scribe</groupId>
        <artifactId>scribe</artifactId>
        <version>1.3.7</version>
    </dependency>


</dependencies>

I had the same issues in eclipse when first time installed it. Clean up worked for me and closing and opening it again.