Top level gradle build fails with ssl certificate error in downloadJS task

[natashadsilva]

Clone the repository,
Build all : ./gradlew build
Fails building the PatientMonitoringDemo:

:samples:PatientsMonitoringDemo:downloadJS FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':samples:PatientsMonitoringDemo:downloadJS'.
> javax.net.ssl.SSLHandshakeException: com.ibm.jsse2.util.h: PKIX path building failed: java.security.cert.CertPathBuilderException: PKIXCertPathBuilderImpl could not build a valid CertPath.; internal cause is: 
        java.security.cert.CertPathValidatorException: The certificate issued by CN=DST Root CA X3, O=Digital Signature Trust Co. is not trusted; internal cause is: 
        java.security.cert.CertPathValidatorException: Certificate chaining error

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

From this line: https://github.com/IBMStreams/streamsx.health/blob/develop/samples/PatientsMonitoringDemo/build.gradle#L38

I worked around it by adding the acceptAnyCertificate parameter, but some investigation is needed to see if that's the best solution.

import de.undercouch.gradle.tasks.download.Download
task downloadJS(type: Download) {
		src([
			'https://code.jquery.com/jquery-3.1.1.min.js',
			'http://cdn.pydata.org/bokeh/release/bokeh-0.12.0.min.js',
			'http://cdn.pydata.org/bokeh/release/bokeh-widgets-0.12.0.min.js',
			'https://cdnjs.cloudflare.com/ajax/libs/numeral.js/2.0.4/numeral.min.js',
			'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js'
			])
		acceptAnyCertificate true
		dest 'etc/html/health/assets/js'
}