Consolidate build scripts with optional flags

[osowski]

Combine build-gradle.sh and build-maven.sh into a single script that should be the happy path by default, with command flags to alter operation as needed.

• ./build-microservice.sh - Builds microservice components using gradlew
• ./build-microservice.sh -m - Builds microservice components using mvn
• ./build-microservice.sh -d - Builds microservice and then builds Docker image afterwards (should be supported with both default and -m build options)

Let's use Eureka as the first component to consolidate these build options and then we can replicate the same script to other repositories.

[edwinvandegrift]

Initial version committed to repo.

[osowski]

Completed.