bump sbt-scoverage plugin to 1.7.0 (#264)

Author: Francesco Pellegrini

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("com.github.sbt"            % "sbt-release"    % "1.0.15")
 addSbtPlugin("org.scalameta"             % "sbt-scalafmt"   % "2.4.2")
 addSbtPlugin("com.geirsson"              % "sbt-ci-release" % "1.5.7")
-addSbtPlugin("org.scoverage"             % "sbt-scoverage"  % "1.6.1")
+addSbtPlugin("org.scoverage"             % "sbt-scoverage"  % "1.7.0")
 addSbtPlugin("io.github.davidgregory084" % "sbt-tpolecat"   % "0.1.17")