Add Hubble gallery app

metadata/com.derek_s.hubble_gallery.txt

@@ -0,0 +1,26 @@
+Categories:System
+License:Apache2
+Web Site:
+Source Code:https://github.com/derekcsm/hubble_gallery
+Issue Tracker:https://github.com/derekcsm/hubble_gallery/issues
+
+Summary:Discover and read about the Hubble Telescope's best images
+Description:
+Hubble Gallery enables you to browse through all the amazing images and
+descriptions that the Hubble Space Telescope mission released to the public over
+the past 25+ years.
+.
+
+Repo Type:git
+Repo:https://github.com/derekcsm/hubble_gallery.git
+
+Build:1.5.0,20
+    commit=1.5.0
+    subdir=app
+    gradle=yes
+    prebuild=sed -i -e '/maven {$/,+2d' ../build.gradle && \
+        sed -i -e '/crashlytics/,+2d' -e '/fabric/d' build.gradle && \
+        sed -i -e '/Crashlytics/d' -e '/fabric/d' src/release/java/com/derek_s/hubble_gallery/base/HubbleApplicationRelease.java
+
+Auto Update Mode:None
+Update Check Mode:Tags