SEARCH-2318: Add Travis configuration to Insight Engine (#873)

The changes include the following:
* The python scripts for e2e environment creation were moved to this code base
* Mirror to community
* Docker image check
* Unit, integration and e2e tests
* "Snapshots": "latest" docker image from master in quay.io, docker images for "release" branches to quay.io, "master" and * "release" branches snapshots to nexus
* Releases: nexus, s3 staging bucket, quay.io and dockerhub
* Fix for https://issues.alfresco.com/jira/browse/SEARCH-2389

The build is using branches only.

e2e-test/python-generator/templates/search/Dockerfile.template

@@ -0,0 +1,32 @@
+FROM ${SEARCH_IMAGE}
+
+# Create search_config_setup.sh if it does not exist (e.g. on SearchServices 1.2.x or earlier).
+USER root
+RUN touch $${DIST_DIR}/solr/bin/search_config_setup.sh \
+    && chown solr:solr $${DIST_DIR}/solr/bin/search_config_setup.sh
+USER solr
+
+RUN replacementPairs=(${SOLRCORE_REPLACEMENTS}); \
+    for replacementPair in $${replacementPairs[@]}; \
+    do \
+        sed -i '/^bash.*/i sed -i "'"s/$$replacementPair/g"'" $${DIST_DIR}/solrhome/templates/rerank/conf/solrcore.properties\n' \
+        $${DIST_DIR}/solr/bin/search_config_setup.sh; \
+    done; \
+    if [[ "${SOLRCORE_PROPERTIES}" != "" ]]; \
+    then \
+        sed -i '/^bash.*/i echo "\n${SOLRCORE_PROPERTIES}" >> $${DIST_DIR}/solrhome/templates/rerank/conf/solrcore.properties\n' \
+        $${DIST_DIR}/solr/bin/search_config_setup.sh; \
+    fi
+
+USER root
+RUN mkdir -p /opt/alfresco-search-services/keystore \
+    && chown -R solr:solr /opt/alfresco-search-services/keystore
+USER solr
+
+# Set the search log level if requested.
+RUN if [ "${SEARCH_LOG_LEVEL}" != "" ] ; then \
+  sed -i '/^bash.*/i sed -i "'"s/log4j.rootLogger=WARN, file, CONSOLE/log4j.rootLogger=${SEARCH_LOG_LEVEL}, file, CONSOLE/g"'" $${DIST_DIR}/logs/log4j.properties\n' \
+  $${DIST_DIR}/solr/bin/search_config_setup.sh; \
+fi
+
+VOLUME ["/opt/alfresco-search-services/keystore"]