Merge #65: descriptor: fix FromStr impl for elcovwsh descriptors

ebeb008 descriptor: fix FromStr impl for elcovwsh descriptors (Andrew Poelstra)

Pull request description:

  Fixes #63

ACKs for top commit:
  RCasatta:
    utACK ebeb008

Tree-SHA512: 719edb4b7ada13ac27a107e5cbc41f728cf16b1b6994fad8a6859e8fc0d9f1c566d0f68f6e0e30fae3739cbfd88cc707336fb6f061a06fa03ef11c88331ab14a

src/descriptor/mod.rs

@@ -148,7 +148,7 @@ impl FromStr for DescriptorType {
             Ok(DescriptorType::WshSortedMulti)
         } else if s.len() >= 3 && &s[0..3] == "wsh" {
             Ok(DescriptorType::Wsh)
-        } else if s.len() >= 6 && &s[0..6] == "covwsh" {
+        } else if s.len() >= 8 && &s[0..8] == "elcovwsh" {
             Ok(DescriptorType::Cov)
         } else {
             Ok(DescriptorType::Bare)