Advance version, and drop Java 7 support (#176)

* Advance version, and drop Java 7 support

Advanced the version to 1.8.0 as Java 7 support is being removed.

* Remove build settings for Java 7

Removed the configuration for Java 7, and switched to trusty for access
to openjdk8.

.travis.yml

@@ -1,6 +1,6 @@
 language: java
 jdk:
- - openjdk7
- - oraclejdk7
+ - openjdk8
  - oraclejdk8
-sudo: false
+sudo: false
+dist: trusty

pom.xml

@@ -6,7 +6,7 @@
  <artifactId>amazon-kinesis-client</artifactId>
  <packaging>jar</packaging>
  <name>Amazon Kinesis Client Library for Java</name>
- <version>1.7.6</version>
+ <version>1.8.0-SNAPSHOT</version>
  <description>The Amazon Kinesis Client Library for Java enables Java developers to easily consume and process data
  from Amazon Kinesis.
  </description>
@@ -131,8 +131,8 @@
  <artifactId>maven-compiler-plugin</artifactId>
  <version>3.2</version>
  <configuration>
- <source>1.7</source>
- <target>1.7</target>
+ <source>1.8</source>
+ <target>1.8</target>
  <encoding>UTF-8</encoding>
  </configuration>
  </plugin>