Issues in readme for microprofile-config QS

(2) Consider adding standard sections - see other (non-MP - because these were not yet tested)

• Use of the EAP_HOME and QUICKSTART_HOME Variables
• Run the Quickstart in Red Hat JBoss Developer Studio or Eclipse
• Also consider using standard sections "Build and Deploy the Quickstart" and "Access the Application" instead of "Solution"

(3) EAP_HOME is used when starting the server, but JBOSS_HOME is used later in the step-by-step instructions to refer to the same path. Consider updating the text (and code accordingly) to use one of {{ EAP_HOME}} / JBOSS_HOME throughout the quickstart.
(4) The quickstart contains arquillian tests but readme does not mention them. Please also add prerequisites for running the tests because when running them with out-of-the-box server and QS there are failures:

[ERROR] Tests run: 7, Failures: 1, Errors: 1, Skipped: 0, Time elapsed: 4.372 s <<< FAILURE! - in org.wildfly.quickstarts.microprofile.config.MicroProfileConfigIT
[ERROR] testConfigSourceReloadedValue(org.wildfly.quickstarts.microprofile.config.MicroProfileConfigIT)  Time elapsed: 0.029 s  <<< ERROR!
java.nio.file.NoSuchFileException: null/custom.properties
	at org.wildfly.quickstarts.microprofile.config.MicroProfileConfigIT.testConfigSourceReloadedValue(MicroProfileConfigIT.java:181)

[ERROR] testConfigPropertiesValue(org.wildfly.quickstarts.microprofile.config.MicroProfileConfigIT)  Time elapsed: 0.013 s  <<< FAILURE!
org.junit.ComparisonFailure: expected:<My[PropertyFile]ConfigValue> but was:<My[EnvProp]ConfigValue>
	at org.wildfly.quickstarts.microprofile.config.MicroProfileConfigIT.testConfigPropertiesValue(MicroProfileConfigIT.java:84)

(5) Missing section on how to undeploy the QS. Standard section Undeploy the Quickstart can be used.