Falha ao inserir dados no banco com o Hibernate

<dependency>
        <groupId>unknown.binary</groupId>
        <artifactId>hibernate-jpa-2.1-api-1.0.0.Final</artifactId>
        <version>SNAPSHOT</version>
</dependency>
...
<repositories>
    <repository>
        <id>unknown-jars-temp-repo</id>
        <name>A temporary repository created by NetBeans for libraries and jars it could not identify. Please replace the dependencies in this repository with correct ones and delete this repository.</name>
        <url>file:${project.basedir}/lib</url>
    </repository>
</repositories>

<groupId>com.alexandre</groupId>
<artifactId>AcademiaKf</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>

<name>AcademiaKf</name>

<properties>
    <endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>
    
    <dependency>
        <groupId>javax</groupId>
        <artifactId>javaee-web-api</artifactId>
        <version>7.0</version>
        <scope>provided</scope>
    </dependency>
    
    <dependency>
        <groupId>org.glassfish</groupId>
        <artifactId>javax.faces</artifactId>
        <version>2.1.17</version>
        <scope>compile</scope>
    </dependency>
    
    <!-- Primefaces -->
    <dependency>
            <groupId>org.primefaces</groupId>
            <artifactId>primefaces</artifactId>
            <version>6.0</version>
    </dependency>

    <!-- Hibernate core -->
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.2.9.Final</version>
        <scope>compile</scope>
    </dependency>
    
    <!-- Implementação de Entity-Manager do JPA -->
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>4.3.1.Final</version>
        <scope>compile</scope>
    </dependency>
    
    <!-- Driver de conexão JDBC do PostgreSQL -->
    <dependency>
        <groupId>postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>9.1-901.jdbc3</version>
        <!--   <version>9.3-1102.jdbc3</version> -->
        <scope>compile</scope>
    </dependency>
    
    <!-- API do Servlet -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.0.1</version>
         <scope>provided</scope>
    </dependency>
    
    <dependency>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>exec-maven-plugin</artifactId>
        <version>1.2.1</version>
        <scope>provided</scope>
    </dependency>

</dependencies>

<repositories>
    <repository>
            <id>prime-repo</id>
            <name>PrimeFaces Maven Repository</name>
            <url>http://repository.primefaces.org</url>
            <layout>default</layout>
    </repository>
    <repository>
        <id>unknown-jars-temp-repo</id>
        <name>A temporary repository created by NetBeans for libraries and jars it could not identify. Please replace the dependencies in this repository with correct ones and delete this repository.</name>
        <url>file:${project.basedir}/lib</url>
    </repository>
</repositories>

<build>
    <plugins>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.2</version>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>1.7</source>
                <target>1.7</target>
                <compilerArguments>
                    <endorseddirs>${endorsed.dir}</endorseddirs>
                </compilerArguments>
            </configuration>       
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <version>2.3</version>
            <configuration>
                <failOnMissingWebXml>false</failOnMissingWebXml>
            </configuration>
        </plugin>

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <version>2.6</version>
            <executions>
                <execution>
                    <phase>validate</phase>
                    <goals>
                        <goal>copy</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>${endorsed.dir}</outputDirectory>
                        <silent>true</silent>
                        <artifactItems>
                            <artifactItem>
                                <groupId>javax</groupId>
                                <artifactId>javaee-endorsed-api</artifactId>
                                <version>7.0</version>
                                <type>jar</type>
                            </artifactItem>
                        </artifactItems>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>